Ossuary poltergeist??

[Solberg]

Men im hitting it with fire dar at level 6 and nothing
Im mage level 12
all elemental powers
int 35 percp 40
elemental 33

Decided to post will try other spells now

[Solberg]

deep freeze, fireball , supernova all nothing

Finally went nuts and hitted him with my nice dagger(attack 5) and killed it, is this the only way?

[SpottedShroom]

Yes, Poltergeists have the best resistances of any entity in Book I. They resist 100% of elemental attacks, in addition to toxins and disease. Pure magick attacks like Compress Atmosphere and Fleshboil will work 80% of the time, though.

[Kreador Freeaxe]

What SpottedShroom said. Compress Atmosphere is about the only Elemental spell I've found to have much effect on poltergeists. They're the biggest challenge to trying to do a pure magic user who never attacks anything with a physical attack.