Corrupt Arcana

(Heroes of Horror, page 120, DnD 3.5)

[Tainted]

You can prepare and cast corrupt spells.

Prerequisite

Spontaneous arcane or divine caster, mild depravity

Benefit

If you have access to a corrupt spell in written form--on a scroll, in a spellbook, or in a tome of forbidden lore--you can prepare it in the same way that a wizard or cleric would. The prepared corrupt spell remains in your mind and occupies one of your daily spell slots until you cast it or change it. A prepared corrupt spell uses a spell slot of the spell's normal level, and you must pay corruption costs as normal for casting the spell. Any corrupt spells you prepare by using this feat do not count against your total spells known, just your spells per day.