For death, important spells include:
Drain Life
Summon Spectre
Well of Misery
Reanimate Archers
Revive Bane Lord
Bane Fire
And of course raise skeletons, though that is really normally researched early game.
Some other handy mid game spells:
Relief
Horde from Hell
Thunder Strike
Blade Wind
Falling Fires
Falling Frost
Contact Lamia Queen
False Horror
Frozen Heart
Mother Oak
Gift of Health
Bind Ice Devil
Soul Slay
Nether Darts
Awaken Ivy King
Pheonix Pyre
EDIT: Misread it, thought you were playing Ermor.
