Namor the Sub-Mariner

Two engines wired into one three-drop, and they feed each other by design. The body scales with a board state the card also builds: power equal to your Merfolk count, on a creature that manufactures Merfolk off your blue spells. That token clause is the wrinkle worth sitting with, because it triggers on cast rather than on resolution. Point a counterspell at something and the fish arrive whether or not the counter connects; even a countered counter still pays out. It also counts blue mana symbols in the printed cost, so a double-blue spell makes two tokens and a triple-blue spell makes three, rewarding a deck that commits to the color rather than splashing it. Every counter, every blue removal spell, every draw ritual you were casting anyway leaves bodies behind, and each of those bodies retroactively pumps the flier that made them. Namor counts himself, so his power never starts below 1, and the 4 toughness holds the whole thing up while the tokens accumulate. Merfolk lords have almost always meant tribal aggression: creatures that pump the team by counting the tribe. This one inverts that reflex, making the tribe a byproduct of a spell-heavy blue deck rather than the deck's whole point. The threat and the token generator are the same permanent, so answering one problem does not solve the other: kill him and you keep the fish; leave him and every blue spell steepens the clock.