A-Karn, Living Legacy

This is the Karn built to feed a machine rather than protect himself. Every previous incarnation of the character has leaned on defense or artifact-hate as a survival mechanism; this one has no minus-loyalty tick short of the ultimate, which means his only way to climb is the Powerstone-making plus, and his only way to dig is the zero that costs mana rather than loyalty. That is the design tension: the plus generates artifact-restricted ramp, the zero converts that ramp into card selection, and the loop is self-sustaining only if you already have somewhere for colorless mana to go. Powerstones are the throttle. They tap for that can't cast nonartifact spells, so the value engine points inexorably toward an artifact-heavy shell rather than a generic goodstuff pile. The ultimate then cashes the whole board of artifacts (Powerstones included) into a repeatable damage emblem, closing the arc from mana rock to win condition. Because the plus is his only means of climbing loyalty, this Karn is unusually exposed to a board that swings back: with no defensive tick, a Powerstone token is small consolation against creatures that can simply attack him down. The A- prefix marks the Alchemy rebalance, tuned for the digital economy where a four-mana ramp walker needs different loyalty math than paper allows. Read the paper original and the rebalanced version side by side and you get a clean case study in how loyalty budgets shift when the format around a planeswalker changes.