You are so familiar with a mastered spell that you can spontaneously cast it, converting other prepared spells into that spell.
Prerequisite: Spell Mastery ability.
Benefit: Each time you take this feat, choose a spell that you have mastered with Spell Mastery. You may now convert prepared arcane spells of that spell's level or higher into this signature spell, just as an Acolyte of good allegiance may spontaneously cast prepared spells as cure spells.
Special: You may gain this feat multiple times. Each time you take the feat, it applies to a new spell that meets the prerequisites.