Returning more in topic with the thread, to me the Spellsplinter Maneuveur seems like a better version of the Mage Slayer feat (better because imaginary Xykon and real Durkula didn't seem to realize that they couldn't cast defensively).
But while I'm writing I'm realizing that this proabably has been already analyzed and, if dumped, there must be a reason I can't see at the moment.