Thassa's Devourer

The 2/6 body is the giveaway: this is a mill engine wearing the armor of a wall. The design leans on constellation to distribute the payoff across a permanent type the deck already runs, so every enchantment that resolves shaves two more cards off a target library while the toughness holds the ground long enough for those increments to add up. The math is what governs the card. Two per trigger is glacial against a lone attacker, so it only earns its slot when the enchantments are stacking: a board where each new aura, each god, each enchantment creature adds another tick to the count. That fat backside matters precisely because milling a whole library to zero is the slowest clock in the game, and a card built to run that clock has to survive the turns it takes. What it represents is a particular answer to the perennial problem of making mill a deck rather than a party trick: instead of one self-contained engine that draws hate, the win condition is a byproduct of doing everything else the deck wants to do. It is quiet by intent, assembling its lethal total in two-card chunks while it defends the position that lets those chunks accumulate.