Thought Distortion
4BB
Sorcery
This spell can't be countered.
Target opponent reveals their hand.
Exile all non-creature, non-land spells from their hand and graveyard.

This spell can't be countered.

That's a pretty brutal line right there. Against a lot of the format this will win the game on the spot. But against a lot of the format it's a do nothing, so it's clearly only viable as a sideboard card. Is a six mana sideboard card worth building around? Is there anything this goes into already existing? I mean, if you were on say, UW Miracles and wanted a sure-fire way to win the mirror, just splash black and here you go. Or if you're in a big mana deck that has black in it and need to beat something like Miracles, well, boom goes the dynamite.

I don't know if this is actually Legacy playable, if it is, I'm pretty sure it is, but as a fringe sideboard card, but man does this thing resolving just wreck people.