Heaven // Earth

In Commander, Heaven // Earth punches above its mana cost because the split structure handles two different crisis states: Heaven sweeps a sky full of tokens or evasive threats at whatever X you can afford, and Earth answers a board-stall or combo-land setup by bouncing every land to hand. Competitive formats barely notice it — Modern and Legacy have faster, more reliable answers at lower costs, and the X-spell ceiling on Heaven is too slow when games end on turn four. Pioneer is the only non-rotating constructed format where it's even worth considering, and there it's a fringe option at best, outclassed by dedicated sweepers. Oathbreaker is the one other format where the flexibility matters, since singleton construction rewards cards that answer multiple problem types.