Spellfire deserves love. [3.5, Spellfire, PEACH]

[Amechra]

Raw Arcane Might [General]
Your every action is filled with a might that could only come from deep arcane forces.
Prerequisites: Constitution 13, Spellfire Wielder
Benefit: For the purposes of prerequisites you are capable of casting arcane spells of a level equal to either your Constitution modifier or one-half your character level (minimum 1), to a minimum of 0, whatever is lower.

Spell Eater [General]
You ache with a thirst for arcane magic. It makes sure you get what you want, at least...
Prerequisites: Constitution 13, Spellfire Wielder, Mage Slayer
Benefit: Whenever a spellcaster that you are threatening fails to cast a spell, you absorb a number of spell levels equal to the spell level of the spell that failed.
Special: Upon taking this feat, you gain a permanent -4 penalty to your caster level. This stacks with the penalty from Mage Slayer and any feat that has it as a prerequisite.