le siblings
So the siblings I’m referring to are Edin, the protagonist, and Damon, the villain. Yes, they’re brothers. Yes, they’re also twins. Nope, they’re not identical twins—they’re fraternal twins, even though they look astonishingly alike 
oh, and fun fact, Edin is the older twin, which may or may not surprise some people.
Well they’ve had a rather interesting relationship, which changes throughout the course of the series and their lives as a whole. Here’s a timeline, sort of.
Ages 0–4
Back when both brothers were precious little beans—even someone as irredeemable as Damon was once innocent 
The two had a healthy relationship. Edin thought of Damon as a close companion, someone to play tag with while their parents were away doing, uh, things 
he also saw Damon as a leader because he’s the more assertive kid. And, this may shock you, but he used to see him as a more caring kid too. Before Damon got tainted by sorcery, he had a more sympathetic soul. Edin also thought of Damon as someone strong and cool since he could do magic whereas Edin himself couldn’t.
In return, Damon saw Edin as a brother whom he must protect at all costs. You heard that right—Damon was one of the OG members of the Edin Protection Squad 
before he did a full 180 
he saw Edin as a loyal and reliable follower, someone he knew would be by his side whenever he was up to something. Edin’s lack of confidence also made him look timid in Damon’s eyes.
Unfortunately for the duo, their relationship was going to go downhill from there
5–8
This is when things started to change between the two. At about four or five years old, their father introduced Damon to the art of sorcery: dark magic. The use of dark magic corrupts the soul of whoever uses it, and if not treated in time, the corruption becomes permanent. I think you can see where this is going
So Edin still saw Damon as an assertive leader, and he also saw him as the smarter brother. However, as Damon aged, he seemed colder and meaner. Damon used to be Edin’s unofficial guardian and close companion, but it all changed during that fateful day when Damon threw Edin under the bus for the first time, which resulted in Edin being cursed by his own father Edin didn’t know how to take his brother’s change of heart. He thought of him as a brother who had lost his way and wanted to bring him back to his old, caring self.
As for Damon? He saw Edin as weak. Not just weaker than him, but just plain weak. As the two grew older and his sorcery further corrupted him, Damon thought of Edin as a pawn more than a loyal sibling. When Edin pleaded with him to go back to his caring self, Damon thought that Edin was immature and stuck in his ways.
And it only gets worse from there.
8–13
When the pair were eight years old, both of their parents were ambushed and murdered by the Guild of Gifted Guardians. Their maternal relatives, the Illenræn Clan, took custody of them from then on. All of them—with the exception of their younger cousin, Lilith—were guardians, unlike their sorcerer parents. The two siblings took this shift quite differently.
Edin was so glad to be living with his maternal relatives rather than with his parents. Not that he hated his parents, because he was still a small child who didn’t know how to really hate them, but he knew they were bad people and let’s just say that they didn’t treat him well his parents favored Damon over Edin, who was showered with praise, attention, and affection; Edin was more accustomed to insults, beatings, and other things so he was very happy to live with good people who didn’t look down on him for his lack of magic or pressure him into doing evil things.
In contrast, Damon hated it. Being in that household meant that he could no longer practice sorcery—openly, at least. Unlike his parents, his uncle and aunt were not afraid to reprimand and even punish him for his bad behavior. So he acted the part. Also, since he had been practicing sorcery for at least three years, Damon’s soul was beyond redemption at that point and the corruption was permanent
Edin thought of Damon as a rebel, a hothead, someone who was used to being spoiled by their parents. Gone was the warm brother he knew in his early years. Damon was cold, uncaring, and docile on a good day. And when their maternal relatives started educating them, Edin saw Damon as a smart—albeit snarky—kid who was also rather snobby.
In contrast, Damon saw Edin as a weak puppet who was too soft and fearful. And, as their maternal relatives started educating the two, he also saw Edin as particularly stupid and inferior. Edin was a disgrace to their paternal legacy in his eyes.
The two still had good moments every now and then. If Damon felt like it, he and Edin would go play tag or some other childhood game. Don’t let it fool you like it fooled Edin—it was all an act to look like a normal kid. Yes, even his playful side was a façade
14–18
So, some more context before I detail how the siblings felt about each other. Most gifteds—people born with special abilities—would go on to become guardians, whose main tasks were to slay wild beasts and kill sorcerers. Since Edin and Damon were both gifteds who were being raised by guardians, it was only natural for their relatives to push the duo into pursuing the path of a guardian. Edin wasn’t opposed. Well, Damon—I don’t really need to say it, do I?
Anyway, while Edin and Damon were being raised, they were also told more about what exactly their parents did. Their parents did very serious crimes that aren’t child-friendly, so the Illenræns waited till they were older before they could delve deeper into their parents’ history oh, and back then the brothers didn’t know that the guardians were responsible for killing their parents. That fact was also revealed later.
Edin, being the good boy he was, automatically sided with the guardians and his mother’s side. Damon was the opposite, siding with sorcery and his paternal legacy. Damon still put up his act of being a dutiful nephew, but in secret he was already honing the art of sorcery and formulating a plan to take the good side down. When Edin caught Damon practicing sorcery, Damon threatened to kill Edin if he ever told anyone, killing a creature right in front of his brother’s eyes and threatening to do likewise if he didn’t keep his mouth shut. Damon was also convinced that sorcery was a misunderstood magic and that the guardians were wrong to suppress it and his paternal side for pushing it. He tried to get Edin to join him, but to no avail.
Edin saw Damon as someone who was in desperate need of being saved. He saw Damon as smart, strong, skillful, and talented, but also as someone who was cold, cunning, diabolical, and misled. He felt that Damon was manipulating him too, but he didn’t know how to put a stop to it.
On the other hand, Damon thought of Edin as someone who was swallowed up by propaganda and incapable of thinking for himself or thinking more rationally. He was inferior in many ways—stupider, weaker, less skilled, untalented, too soft and too emotional. He even thought Edin was disloyal! Edin used to stick by Damon’s side back when they were still very young, but now, Edin had sided with his “distant” family and the guardians—the same people who murdered their parents. It was starting this period when Damon considered Edin a target.
18–21
And if you think that wasn’t bad enough, ho boy, it gets even worse from here. In his late teen years, Edin finally gathered the courage to tell the Illenræns that Damon had been a sorcerer the whole time. Damon wasn’t pleased to hear it. So what did he do? He ran away from home.
Well, not just that, but the two had a confrontation. Edin caught Damon trying to run away from home and confronted him on the land just outside the castle—yes they lived in a castle. They talked, Damon responded with a fireball, and the two brothers legit dueled against each other for the first time. This was no practice sparring session; it was a proper duel to the death. Edin would’ve died had it not been for the intervention of his cousin, who took a longer time to realize that Damon had escaped. Damon retreated into the wilderness, knowing that he wasn’t strong enough—yet—to take on many gifteds on his own.
And then came the wedding tragedy, which happened when both brothers were twenty-one years old. Loren, their cousin, was supposed to wed the love of his life. Edin couldn’t attend because of, uh, circumstances, so the rest of the family went without him. They didn’t return home for a few days after the wedding date, which made Edin curious. He went out. He bumped into his brother and realized that he was the one who murdered everyone—except for one person—at the wedding, including their last remaining family. And then they had another duel, which Edin lost.
It was during this period that Edin started feeling resentment towards Damon. At first he thought that Damon could be redeemed, but soon realized that there could be no more redemption for him. He saw him as evil, heartless, and—this made his heart break—someone who must die.
Damon’s opinion of Edin didn’t change much. He did consider Edin a target, but he wasn’t sure whether to kill him outright or somehow turn him into a tool. Eventually he decided to try manipulating him instead. So after he won their second duel, Damon didn’t kill Edin outright—he put an amnesia curse on him instead, and maybe a gradual death curse because why not. With Edin’s memories gone, Damon hoped to be able to manipulate him into joining his side later in life. Edin was no brother—he was a tool.
Blood Will Tell — Act I — Ages 21–26
Thanks to none other than his murderous brother, Edin got his memories wiped. He couldn’t remember anything that happened before the day he got rescued by Arden, the deuteragonist of the trilogy. That also meant that he totally forgot that he was blood brothers with the realm’s most evil and powerful menace. While Damon was wrecking havoc throughout the realm, Edin was busy training under Arden’s tutelage. He didn’t think of Damon at all until much later. Damon, on the other hand, was wondering whether Edin was alive or dead.
Then they met again near the end of Act I. Edin had no idea who Damon was other than “bad guy who I must stop at all costs,” so when he sees him for the first time in years, he straight up tries to murder him. And Damon retaliates. Edin gets knocked out during their fight, and before Damon can do anything more, Arden steps in to save Edin and whisks him away. The brothers would meet again at the end of Act I—Arden and Damon were battling in a cavern when Edin rushed to join Arden’s side. Edin was knocked out by Damon, again, and it looked like the latter was going to win when he managed to injure Arden as well. There was just one problem: his strike made Arden bleed, which triggered Edin’s bloodlust curse, which meant that Edin went from poor-cinnamon-roll-who-was-straight-up-unconscious to mindbogglingly-powerful-and-terrifyingly-bloodthirsty-and-unstoppable-warrior who almost singlehandedly killed Damon. If Damon didn’t escape, Edin would’ve killed him then and there.
Due to his amnesia, Edin’s previous relationship with Damon didn’t affect how he felt about him then. In his mind, Damon was just a really powerful evil guy that they had to kill.
Damon had a lot more to say of his brother, on the other hand. The current Edin was a much luckier bastard compared to pre-amnesia Edin. He was also much stronger than he remembered. As far as powers were concerned, Damon no longer considered Edin a weakling. He still considered him a pawn though, and with his memories wiped, Damon was eager to use him as the tool he intended him to be.
Blood Will Tell — Act II and Act III — Age 26
So Damon kickstarts his plan into action. All gifteds have the ability to communicate telepathically with close blood relatives and people close to them. So what does he do? He uses this to enter Edin’s mind and taunt him through telepathy. He goes, “Hey there, did you know that we’re actually related?”
At the same time, Edin has managed to uncover parts of his past, including the fact that he’s cousins with Arden’s late fiancé, Loren Illenræn. So when Damon tells him that they’re related, Edin tries to deny it, saying that there’s no way he can be related to Damon and Loren at the same time.
Poor guy, there is a way for that to happen
Anyway, Edin starts thinking of Damon as a nuisance for popping into his head and refusing to leave—Edin wasn’t skilled enough in telepathy to push him out—in addition to being an evil guy who must die. He’s also scared of what his connection to Damon could entail—if the two were close in the past, does that mean that Edin was a villain before his memories got wiped?
And on the other side, Damon was having the time of his life taunting his brother while recovering from their last big battle. He still saw Edin as someone he could use, someone he could twist into joining his side.
Damon doesn’t get to use telepathy to manipulate Edin for the whole book, to Edin’s luck—at the end of Act II, Arden severs the link between his and Damon’s minds.
Act III is where Edin realizes that he is indeed Damon’s biological brother in addition to being Loren’s biological cousin, which sends him into a crisis. After he recovers some memories regarding his past, which he keeps to himself out of fear that he’d be ostracized for being related to Damon, he then becomes determined to kill Damon himself. The two brothers meet in another battle at the end of Act III, where Edin confronts Damon regarding their shared past. Damon tells his version of the past events. He tells Edin that the guardians murdered their family, which is true; and tells him that he’s out to avenge his family’s deaths, which is also true; but he also conveniently leaves out the fact that their parents and father’s side were all evil Edin refuses to join him at first. The two battle, Damon defeats Edin, and uses his magic to absorb Edin into his body so that they become a singular entity, two minds sharing one body.
At the end of Act III—and the book itself—Edin thought of Damon as someone cruel and heartless. How dare Damon kill off his own family—after all, Loren and the rest of the clan were his blood relatives too! Edin also felt that it was his duty to stop Damon once and for all. Edin failed to stop Damon back when they were younger, so he sought to “right his wrong” by going on a solo mission to stop him himself.
Damon, on the other hand, thought Edin was stupid for refusing to join him when he offered, and for dismissing Damon’s “truth” as “lies.” He still saw him as a tool for the most part. However, he also saw him as a brother who had been led astray and must be brought back to the path that their parents had paved for them.
Blood Will Boil — Act IV and Act V — Age 26
This book is where it gets extra spicy. While the guardians work to uncover Edin’s past, which the Illenræns had tried to bury before they all got killed off, Edin and Damon were quarreling in their shared headspace. Damon’s been trying to convince Edin to join him by revealing stuff about their past, while Edin tries to dismiss them as “lies” even though he has a sinking feeling that the stuff that Damon’s telling him is true.
And to his credit, it is true—Damon just leaves out the rest of the truth to manipulate Edin into thinking that the guardians are the bad guys who massacred their clan without a good reason
Edin’s opinion of Damon experiences a turning point when Edin manages to connect with his former mentor, Arden, telepathically. She confirms that yes, the guardians did kill off his parents and the rest of his dad’s side, and she accidentally let slip that she snooped into his diary unfortunately, she was not able to tell him that his family was evil which was why they were killed off in the first place; Edin was too furious and hurt to hear and cut off the connection before she could explain.
Now Edin sees Damon as someone who’s been misjudged and someone who’s been telling the truth the whole time. Though he doesn’t agree with Damon’s mass murder tactics, he no longer sees him as purely an antagonist.
Damon, having realized his brother’s shift in perspective, starts to see him as an ally in addition to being a tool he can manipulate. He starts to see him as a loyal brother again, like when they were much younger.
At the start of Act V, the Guild announces that ED—the shared body of Edin and Damon—must die, which means that Edin must be killed along with Damon. Edin feels even more betrayed by the people he used to fight for. Damon jumps on the chance to invite Edin to his side, and Edin finally agrees. Edin no longer sees Damon as a threat, but as someone out for rightful revenge. He sees him as someone he should support in the fight against injustice. Damon, on the other hand, sees Edin as more of an ally and brother than a tool, now that he has gained Edin’s loyalty.
So from that point on, the two go from being simply blood brothers to Mass Murder Brothers
And then a shift of perspective changes again at the end of the book! Edin and Damon face off against the remaining guardians—well, a chunk of them anyway—in a boss battle, nearly winning until Arden—Edin’s former mentor and the realm’s strongest guardian—enters the battlefield and subdues them. Arden first orders Edin to stop. Damon wants to kill Arden because, you know, they’re archenemies and all, but Edin is reluctant to kill his former mentor. This makes Damon furious, so he seizes full control of their shared body in an attempt to kill Arden. When this happens, Edin tries his best to restrain his brother. Arden eventually paralyzes them and uses her telepathy to enter their headspace. Arden and Edin then have another tense talk in his mind. Arden cuts her hair in front of Edin to reveal an eyeless socket—a scar from the wedding tragedy, which she got thanks to Damon. This sends Edin into a shock. Arden tells Edin that, hey, your entire family was evil and they were all killed, and you shouldn’t choose the brother who’s literally tried to murder you multiple times over the person who saved and stood up for you even though you were a literal stranger. Yeah, their conversation was intense, to say the least
Edin’s view of Damon shifts again at the end of the book. Edin realizes that Damon’s been manipulating him through half-truths and sees him as the manipulative monster he is. He reverts to thinking of him as a cruel, evil, deceitful, irredeemable, and someone who must die. With Arden’s help, Edin splits from Damon and the two brothers go back to having separate bodies instead of sharing one.
At the end of the book, Damon thinks of Edin as a traitor for deserting him and no longer sees him as a brother, but a target he must kill. He goes from seeing him as an ally to wanting to murder him for leaving his side again. He doesn’t even consider manipulation an option anymore, thinking that he’s too far blinded by the guardians’ propaganda.
Out for Blood — Act VI and Act VII — Ages 26–28
The interesting thing about Act VI is that Edin stays unconscious for, like, most of the act. Yup. He spends about 1/7 of the entire trilogy just knocked out cold 
while Edin’s stuck in a coma, he gets his memories back. He wakes up at the tail end of Act VI with his memories back, and that’s when he remembers how horrible Damon is and is filled with even more fury towards his brother. As for Damon? His view of Edin doesn’t really change from his view of him in Act V.
Act VII, two years after the events of Act VI, is where things get interesting. After Edin and Damon split, their telepathic connection somehow got restored. Edin accidentally goes into Damon’s mind during a dream. Instead of having their connection severed, he and the guardians decide to use it to spy on Damon instead. Damon catches Edin spying on him through telepathy though well not to worry. Arden’s managed to teach Edin how to block Damon out of his mind, so they’ve got that part handled.
Their feelings toward each other don’t change until the final battle, where Edin plunges his sword through Damon’s heart and finally kills him. Near the end of the book, while the entire realm is celebrating Damon’s death, Edin excuses himself to do some “unfinished business.” He piles up the corpses of his evil family, Damon included, with the intention to set them on fire and cremate them. Before he uses his fire powers to burn the bodies, he looks at Damon’s dead face. Seeing him so peaceful makes Edin almost—keyword: almost—feel sorry for him. Yes, he was terrible and deserved death and worse than that, but seeing him actually dead made Edin wonder whether Damon would’ve been a villain if he was born without magic. It’s less of an “I feel sorry now that you’re dead” feeling but more like a “what we could’ve been, had you not been corrupted” feeling.
So yeah, that’s it. That’s what Edin and Damon thought of each other
Doesn’t have to be main characters. Anyone you want but pick just one.