Infesting Radroach

A 2/2 flier that refuses to block is a familiar aggressive silhouette; what this one does with the graveyard is not. Because it can't block, it lives to attack, and its combat trigger loads rad counters onto whoever it hit. Those counters do the milling, and the milling is exactly what buys the creature back: any opponent milling a nonland card while this sits in your graveyard returns it to your hand. The braid is the point. Two graveyard-facing systems feed each other, so the damage it deals becomes the fuel for its own recursion, and a chump block or a trade only delays the next attack rather than ending it. The "can't block" clause is what pays for that resilience: a self-returning evasive threat that could also wall up on defense would be too much of both, so the design trades away the block to earn the loop. It closes a gap most evasive beaters leave open, the one where dying is supposed to mean staying dead. Here, as long as the rad counters keep pushing nonland cards into an opponent's graveyard, dying is just a step in the cycle.