Finale of Devastation combines creature selection, graveyard recovery, and a late-game combat payoff in one spell. It searches your library and/or graveyard for a creature with mana value no greater than X and puts that creature onto the battlefield. That makes it useful before a finishing turn, when finding a utility creature or an engine piece is the immediate priority.
At smaller values of X, you can find Eternal Witness to recover another card or Bloom Tender to improve future mana production. Because the creature enters directly, you receive its entry abilities, but you are not casting it. That distinction matters for effects that trigger when you cast a creature spell. The option to search the graveyard also helps recover a creature that opponents have already answered.
When X is at least ten, your creatures get +X/+X and haste until end of turn, including the creature Finale finds. Choosing X equal to ten normally means paying twelve mana in total. Craterhoof Behemoth is a powerful target because its entry ability supplies trample and another boost, helping a wide board push through blockers rather than relying on size alone.
Large-mana engines such as Nykthos, Shrine to Nyx can make that mode reachable in a developed game. Bloom Tender with Freed from the Real offers a repeatable mana combo that can also fund a very large Finale. You still need the search spell to resolve and a combat plan that survives interaction. Treat Finale as a flexible tutor throughout the game, with the finishing mode as a payoff for the mana your deck is built to generate.
