Can't use sacrifice in battle with giant spider?
 

I'm playing as a mage on hard, I cast hypnotize on a stack of some 120 venomous spiders, and in the next round I wanted to sacrifice them to resurrect my badly depleted stack of sprites - the dang spider targeted them a couple of times instead of summoning more spiders!

So, what gives? Is there some kind of ban against using certain spells in a battle against bosses? Even though I can use it on my own units! :confused:

Well, I doubt there is any kind of ban. The only ban I know of concerns the rage box, since this is a boss battle..

Try hypnotizing spiders that aren't close to the big spider's field of attack... And I hope spiders can be sacrificed. I noticed that thorns and other summoned creatures can't be sacrificed.

There are some regulations I guess. For example, my inquisitor doesn't seem to want to resurrect the demonesses, but I can. That's aweird thing as well :)

It's probably because the spiders are summoned creatures (albiet summoned by the boss, rather than you).

I think same, summoned creatures cant be sacrificed.

Ah, I see. Thank you.

For this battle, Royal Thorn is king, and makes it a weird easy stuff. Each time the queen spider summon spiders they are spawn on random places so the most place you occupy the less chance you get a spawn.