Calamity of the Titans
Most board wipes deal in absolutes: everything drops to zero regardless of size. This one draws a line instead, and the line is set by the colorless creature you reveal from your hand. Reveal a five-drop and every creature and planeswalker at four mana value or below gets exiled; reveal something enormous like Emrakul, the Aeons Torn and nearly every creature and planeswalker vanishes while your own colossus is never at risk, because the reveal only shows the card and never leaves your hand. That is the quiet elegance of the additional cost: you pay it by proving the card exists, not by spending it, so the giant that calibrates the sweep is still there to cast next turn. The threshold is strict (mana value less than the revealed card's), so the floor pulls its own weight: a cheap reveal draws a line that catches almost nothing, while anything with real size clears the entire low end of the field, tokens at mana value zero included. Because it exiles rather than destroys, it steps past indestructibility, regeneration, and death triggers, and because it catches planeswalkers on the same threshold, it sweeps the full permanent axis a big-mana strategy learns to fear. The catch is symmetry below the line: it does not spare your own small permanents, and with a thin board and nothing large in hand it sits dead. A wrath for decks already casting enormous colorless things, turning the height of your curve into the reach of your answer.
