what if i’m kin with a character who died in canon?

A character being dead canonically shouldn’t affect whether or not you’re kin of them.

As a reincarnated kin myself, I tend to believe them being dead in canon might make it more likely for there to be kin of them out there.

When you’re kin of someone, you’re kin of the whole person, not just of them as they currently are or at one moment of their life. Their whole life and experiences are yours. You are them. They have become you. That is what I believe.

As someone with a death in their canon, you should watch out for particularly strong memories of your death hitting you, as they can be triggered by watching/reading it happening.