Blood Cultist

The pinger archetype, with a feedback loop bolted on. The tap ability is the old tim template that has anchored control creatures since the earliest era of one-damage pingers: a repeatable ground-snipe for mana dorks, X/1s, and anything you want softened before combat. The second ability is where the design earns its name. A creature damaged by this one that dies during the same turn feeds back a +1/+1 counter, so the body grows on the strength of its own kills. The coupling is what makes it a build-around rather than a value engine: at a 1/1, the ping deals exactly 1 and never more, no matter how many counters stack up, so on its own it cannot finish anything sturdier than another 1-toughness creature. The engine has to be fed from outside, with a second damage source or a combat trade that lands the kill on the same turn the ping goes off. That same-turn clause is the real governor. A creature that survives the ping and dies on the opponent's turn returns nothing, so the card rewards setting up the lethal point before you tap rather than pinging into hope. The counters make the body harder to trade with and better in combat, which is where the growth actually pays off, never in the ability's output. A fragile engine whose ceiling lives entirely in how reliably you can route deaths through its own damage.