Quote Originally Posted by Reboot View Post
Well, Maximised Energy Drain is a twelfth-level spell - Energy Drain is ninth level, and Maximise adds three. So he needs to have taken ISC at least three times by #652 (and have the levels to do so).
We've done this several times before. There are Sudden Metamagic feats. There's the Ultimate Magus prestige class. But I happen to agree that he's around level 26 because that works for his casting of Superb Dispelling without magic items. I did the maths here. TLDR: Xykon is level 27 plus or minus his Int bonus, with a minimum of level 23. Level 27 also allows him three picks of Improved Spell Capacity which would give him one 12th level spell. He would need a CHA of 34+ to get more than one.