Necropolis Regent

A snowball engine built to reward an army, not just itself. The trigger watches every creature you control, so each connecting attacker (not only the Regent) banks counters equal to the damage it dealt, and those counters compound across turns the way few combat-damage payoffs do: hit for two, swing for four next time, then eight. A 6/5 flier is already a fast clock, but the design is at its most lethal in a wide board, where a swarm of small attackers all balloon at once and a single unblocked one-drop becomes a multi-counter problem the following turn. The cost is the obvious tax: triple black at six mana asks for commitment, and the counters only land on creatures that actually deal combat damage to a player, which means chump blocks and removal targeted at the attack step turn the engine off before it pays. That fragility is the honest price of an effect that, left alone for even two combat steps, runs away from any board. The Vampire type and the counter-accumulation theme both gesture at the lifeblood-and-growth flavor the creature's faction trades in, but the mechanical heart is older than any one tribe: a payoff that turns connecting in combat into permanent, escalating board state.