Will it work against a Lich? Demi-Lich? Drow? Are they a waste of a spell slot?

what a nishru does is drains the spells and charges from items, its mainly used against casters to temp drain their spells so they cant cast. I think it will work against anything though. the good thing about nishrus is magic heals it, so if a caster casts on it it heals it.

I can work - but some liches summon monsters of their own - and they will make short work of a nishruu.

secondly some liches carry items with charges - and you don't want to get a drained item - do you ;)

Thirdly liches require magicl weapons to hit - and a nishruu's attack isn't considered magical

But they are not a waste of spellslots - they are excelent against enemy magicusers.

<font color="gold">It is not to waste a spellslot to summon a Nishruu. They are good creatures, both in battle and their abilities. But they will not work too well on Liches. ;) </font>

I've had a weird experience with Nishruu's ...
Its was in the Underdark, at that contraption where you release trapped souls.
The mage that only says " uuuhhhh" , and then attacks ...
I summoned a nishruu, the nishruu attacked .. and every time the nishruu hit the mage. it died.
Reloaded several times .. no fireshields .. attacks and dies
Very weird