Dug up some notes, while nothing new, these are the things I found entertaining
DC boost for [evil] - Malign Spell Focus, Enemy of Good, Demonic Conduit
CL boost for [evil] - Tainted Scholar Blood Component, (should be some others around somewhere...)
Damage/effectiveness for [evil] - Violate Spell, Corrupt Spell, Debilitating Spell
Wizard Abyssal Specialist - specialized in [evil], among others, lots of bonus spells
Ritual Sacrifice - Blessing of the Godless, Fell Conspiracy, Sacrificial Mastery/BOVD Sacrifice
And what to do with all that spilled blood - Tainted Sorcerer Blood Component
Last time I was looking at it, I was cooking something thematic tied to Pandorum.
Though I deterred myself from anything beyond skeleton class level ordering, since I had no where to place such a critter in either of my campaigns.
Scion of Pandorum
Arcane 1 / X 4 / Thrallherd 1 / X1 / Subverted Psion 1 / X 12
Cloistered Cleric 1 / Ardent 2 / Psychic Theurge 3 / Ur-Priest 1 / Tainted Sorcerer 1 / Thrallherd 1 / Psychic Theurge 7
Endless blood sacrifice
None of this is particularly T1/CO/TO, but it seemed like good (evil) fun