[Kristoffer O]

> I've read a couple of mentions of this and i do not understand at all. What's the issue here?

Communion slaves are not supposed to cast spells, but currently slaves can cast their spells if they do it before the master does. Thus it might be considered unfair play to organize slaves and masters in such a way that the slaves benefit from the communion to spam empowered spells.

EDIT: OTOH it is a mechanic that is achievable by anyone with a communion so it is more a matter for us on how to make the communion balanced. It would be much to demand that every user of a communion is forbidden to use slaves with lower ID numbers than the masters. So until the communion is fixed I would not hold it against anyone to use this quirk.