Final Struggle

(You may cast a legendary sorcery only if you control a legendary creature or planeswalker.)
Choose one-
Target player must sacrifice a planeswalker.
or
Each player must exile cards until they reveal a nonland card, Put X Loyalty counters on a planeswalker they control, where X is that card's converted mana cost. Discard that card.
KA...ME...aaand will be right back to bring you the epic conclusion to this flavor text on the next card!