Cult monsters bug?

[neptune]

In the ogre tc I had summoned over 10 monsters (I think). When I summoned a black pudding my hp went down. I killed it. Then I noticed my mana going down. I don't have any life stealing creatures. How could this be?

[Salathar]

Normally there should not be any reason for your mana to go down unless you are using it up to cast spells.
However someone invisible could be draining sp off you or perhaps you have accidentally stumbled upon a rune of mana drain?

[bort]

Indeed. Sometimes, though it should be nonexistant, a hostile monster may cast magic drain on you. Though no doubt of it, it was another invisible player. Like me, recharging my Sp.