Luna would be a bird. Because birds can fly. They’re free.
Vincent would definitely be a wolf. Although wolves are pack animals, they can also be rogue and that makes them dangerous.
Ember would be cheetah. They’re fast and somehow cute?
Kenji would be a pen. He doesn’t believe in spirit animals. He rather tells the stories that need to be told.
In that case, it would be more like this: “A time of peacefulness after a disaster or loss”. Since she does solve a mystery and there is a great loss and/or disaster that takes place. Maybe not in apocalyptic proportions but a disaster nonetheless.