Anguish wrote:
Abilities that are mind-affecting are called out as such. The collective ability is not, flavor text aside.
Unfortunately, it isn't possible to convince someone that an absence of a descriptor is deliberate. You're looking for an explicit statement "this is not mind-affecting", but you won't find one just like you won't find "this is not a purple-frog-asteroid-taxation effect", because that's not how this game is written. We don't write what isn't, we write what is (with the exception of exceptions which need to be pointed out.)
How many spiders are you going up against anyway? There aren't very many non-undead, con-construct creatures which are still mindless. Vermin and plants being the obvious ones.
Anyway, take a look at the bestow curse spell in Core. Will negates, not mind-affecting, so there's precedent for such a thing. Clearly that spell is impacting some aura or essence of a creature even if it's mindless, so there's no real reason why a collective can't as well.
The lack of rules is what he is worried about, he feels that if there are no rules then there isn't a game, so yeah just got my character killed and rolled a "healstick" Cleric. However thank you, i'll keep this in mind for the next time I try this class.