This brilliant loop relies on a harsh static environment engineered by Godhead of Awe and Kaervek, the Spiteful, which together impose a permanent base-and-buff reduction that instantly shrinks any creature to zero toughness the moment it touches the battlefield. When you cast Rot Hulk, its enter-the-battlefield trigger ignores the lethal state-based actions long enough to pull both itself and Vengeful Dead straight back out of the graveyard. As those returning bodies immediately succumb to the board-state's math again, Vengeful Dead triggers its own death ability to drain your opponents' life totals with every single iteration.