Beguiler of Wills

Mind control that scales with the board you have already built. Where Control Magic and Mind Control pay a flat price to steal anything, this turns theft into a repeatable, conditional engine: the tap symbol makes it a once-per-turn faucet rather than a one-shot enchantment, and the more creatures you field, the larger the prize it can pull across. That conditional ceiling is the discipline holding it back from being broken. With an empty board the body is a fragile 1/1 doing nothing useful; it wants to be cast into a wide position, where every creature you already control raises the power threshold for what it can reach next turn. The feedback loop is the heart of it: each creature you steal becomes a creature you control, which lifts the ceiling for the next steal, which lets you reach a bigger threat, and so on until the table tips back on its owner. It rewards going wide rather than going tall, an unusual ask for a blue control piece, since the threshold counts bodies, not power. The slow tempo (untap, target, repeat) is the opponent's only window: the 1/1 has to survive a turn cycle before the snowball starts, and any removal answers it cleanly. Left alive on a developed board, though, it dismantles an opposing army one creature at a time and conscripts each of them into raising the bar for the next.