Well, yes. I suppose I'd be on anyone's side rather than the demons'. Though the bandits are bad guys too, aren't they?
Wouldn't it be a good thing to unite all humans, sliths, nephilim, spiders, dragons and all other intelligent species against demons and undead?
By the way, how do you tell if a hostile creature is intelligent? OK, the spiders are definitely not very intelligent, though they can talk, as we know because there are friendly ones. The sliths and nephilims definitely build towns. But what about lizards and drakes? They sometimes seem to have money.