[adamkad1]

>If parted pain activates on that and you can't use aoe or focus it, then that would be blatantly overpowered.
Eh, I think we have worse. Also oooh crap, it was supposed to be shared pain, parted pain is a different thing. Could make them take damage separately. For aoe, it would end with net neutral damage. But if you basic attack 2 mobs on a single tile, both get hit so that sucks. Could make it so shared joy also is the only way to heal the youkai, so all healing you take is cut in half too.

>The youkai attacking at the same time as you sounds like an interesting concept, but your own damage should be nerfed in that case. Or your attack gets replaced by the youkai's but it's boosted. Still I don't know if this is a good idea
That kinda ruins the concept since once again, you cannot get youkai attacks out when you have only one youkai and its installed

>All we really need is for the youkai to count as summoned and nearby for the effects of other skills.
Honestly, that alone doesn't interact with that much stuff. You already get the effect of fight as one.