Erika flaps its arms and utters the magic words (blast vacuum)
Erika hesitates as it casts blast vacuum.
Erika shudders as its blast vacuum hits itself.
Magical rifts open above Erika and hideous rays of POWER combine its spell.
::..:. Erika [Analyze: Erika writhes in agony.]
A large hole replaces Erika's face.
Erika is DEAD, R.I.P.
Erika makes a stirring sound as the parasite experiences immense pain!
Your connection to your parasite is severed completely.

This is how nergal blasters work.