During your precombat main phase, cast Not Dead After All by paying , targeting Xiahou Dun.
Activate Xiahou Dun by sacrificing it, targeting Not Dead After All.
When Xiahou Dun dies, it and Pitiless Plunderer triggers, as well as any Wicked Roles that were attached to Xiahou Dun.
Resolve the Wicked Role trigger(s), if applicable, causing each opponent to lose that much life.
Resolve the Pitiless Plunderer trigger, creating a Treasure token.
Resolve the Xiahou Dun trigger, returning it from your graveyard to the battlefield with a Wicked Role token attached to it.
Resolve the Xiahou Dun ability from step 2, returning Not Dead After All from your graveyard to your hand.
Activate the Treasure by tapping and sacrificing it, adding .
Repeat.
This cunning loop transforms Xiahou Dun, the One-Eyed into a tireless engine of recursion by constantly cheating death. You begin by casting Not Dead After All to protect the commander, then sacrifice Xiahou Dun to its own ability—which brilliantly lets you pull that very same spell right back out of your graveyard and into your hand. Meanwhile, Pitiless Plunderer watches the carnage and dutifully turns each sacrifice into a fresh Treasure token, providing the exact black mana needed to recast the spell and restart the cycle. The Wicked Role token generated along the way merely adds insult to injury, draining your opponents to zero while your immortal warlord dances endlessly between the battlefield and the graveyard.