Corsairs of Umbar

Amass Orcs is a black-red mechanic by tribe: the token it makes is a black Orc Army, so a blue creature that grows the Army on combat damage is a deliberate bridge, handing Orc-counters decks a way into the color that has always owned unblockability. The two halves feed each other. The activated ability spends mana to shove a Goblin, Orc, or Pirate through untouched, and when you aim it at Corsairs itself, connecting is exactly what triggers the amass three, so the same investment that lands the hit also enlarges the Army you keep swinging with. The self-referential wrinkle is that its own attack can be the one you make unblockable, which turns the 3/3 body into a slow but reliable Army engine that scales every turn it gets through. It reads as a support piece rather than a bomb, and the counter-generation is the more durable half: an Army gaining three counters per connection outgrows most blockers faster than the frame suggests, and the unblockable clause guarantees those connections keep happening. The design's real contribution is structural, giving a mechanic that lives in aggressive black-red the one thing those colors chronically lack, which is a repeatable way to make sure the swing lands.