Gisa, Glorious Resurrector

The replacement clause is the whole engine: opposing creatures don't hit the graveyard, they slide into exile under her watch, and your upkeep hands the entire pile back onto your side of the board. That reroutes the usual death-to-graveyard pipeline in a way that quietly shuts off opposing recursion and death triggers as a side effect, since the creatures never actually die and never touch a yard she doesn't control. The natural fuel is a board that dies in bulk: your edicts, your removal, combat you win. But there's a trap built into that fuel source, and it's the whole reason she reads as a puzzle rather than a payoff. A symmetrical wrath will exile the opposing creatures via her replacement effect, but if that same sweeper kills Gisa, the upkeep trigger that collects them never happens: no Gisa on the battlefield, no windfall. She has to survive the deaths she causes to profit from them, so the play pattern rewards one-sided removal and edicts over indiscriminate board wipes. Decayed is the tax on everything she does collect. Reanimated bodies come back unable to block and sacrifice themselves at end of combat if they attack, so you're assembling a one-shot wave, not a standing army: the reward bends toward a single decisive swing rather than a durable stall. The 4/4 body keeps pressure on while exile fills, but she lives and dies on that upkeep collection, and on your ability to manufacture opposing deaths without also killing your collector.