Zimone, All-Questioning

Number theory as a build restriction is the kind of gimmick that usually dies in the reminder text, but here the prime-counting condition is doing genuine design work: it turns land drops into a puzzle instead of a formality. You cannot just play a land every turn and coast, because the trigger only checks the total when your end step arrives, and that total has to be prime. Two lands, then three, then a whiff at four, then a payoff at five, then dead again at six: the sequence forces you to weigh when to hold a land and when to run out an extra to leapfrog a composite number. Because the token's size scales to your land count, the reward grows exactly as the constraint gets harder to satisfy, which is the elegant part. A prime at eleven or thirteen lands is a genuine threat, and the density of primes thins as the numbers climb, so late-game triggers demand deliberate manipulation (fetch effects, extra land drops, bounce-and-replay) rather than luck. Primo, the Indivisible arrives as a 0/0 that immediately becomes as big as your land count, a single scaling body rather than a stream of tokens, which keeps the payoff swingy instead of grindy. She can even hit on the turn she lands: drop your third land, cast her on curve, and you have a prime and a token before you pass. The friction is real, but the math is the point, and it is the rare mechanic that rewards counting as a skill.