Azlask, the Swelling Scourge

The experience-counter mechanic usually attaches to a slow, opt-in payoff: a commander that rewards you for doing some deliberate thing repeatedly over a long game. Here the counting is passive and grim. Every colorless creature you control that dies feeds the count, and an Eldrazi deck is built to make bodies die in bulk: Scions and Spawns sacrifice themselves for mana, get thrown into blocks, and generally exist to be spent. Those dying tokens become the growth engine, so the counter climbs fastest exactly when your board is being ground away. The five-color activation is the release valve, and it does two distinct things: a battlefield-wide anthem scaled to your accumulated deaths, plus a keyword grant that turns your remaining Scions and Spawns into indestructible attackers carrying annihilator 1. That second clause is the sharper design idea, converting disposable ramp fodder into a wave of permanent-stripping threats that no longer die to combat. The WUBRG cost is the honest part of the bargain: a real five-pip tax on a deck that otherwise generates colorless mana by the fistful, so the payoff wants a manabase that can actually reach all five colors on the turn it matters. What makes the design cohere is the loop between its two halves: the more your creatures die, the larger the pump and the more annihilator triggers you can afford to keep alive, so a commander that grows on attrition also supplies the finisher that ends it.