[Perdition]

This skill has an absurdly punishing condition for maintaining it. If you take any form of non status or non field effect type of damage, then it's gone. If you killed any enemies to raise its level cap, then that doesn't matter anymore because the status itself is gone and when you regain it you have to start all over. 

Taking damage is entirely unavoidable with autohits existing, so this passive feels entirely useless. I think instead, for it to begin stacking it should require all of your bonded youkai out. The status is loss upon the start of a round where all of your bonded youkai are not summoned, and it's lost immediately if any of your bonded youkai are killed.

[Autumn]

Given how much of a damage increase it CAN become, it would probably be better to convert this to be more akin to poise, and stack every round, with basic attacks removing the status, this makes it so that a dodgy bonder would have a chance at retaining it, and counterplay to the status being to land a basic attack every once in a while, it does stack up very slowly as is, and requires kills to get uncapped at certain thresholds.

I don't forsee it being much of an issue.