REVENANT

Your dead runs don't vanish - they become the dungeon. Every delver you lose rises as a named, dated revenant that fights the way you fought and wields the relic it died holding, so the gear you came to reclaim is the very thing trying to kill you. Deterministic, perfect-information tactics: read every fight before you take it, shove foes into the chasm, slip past sleeping guards, and haul the Vault Heart back to the surface to win.