Master of Cruelties

A demon that drops an opponent to 1 the moment it connects unblocked, and then deals no damage at all: the design splits the kill into two halves and hands you only the first. The 1/4 body with first strike and deathtouch is built to discourage blocking, because anything that trades into it dies, but the lone-attacker clause is the cost that keeps the effect from being a free win. It cannot swing alongside a board, so the threat it generates is purely about resolving its trigger and finding a way to convert a one-life opponent before they untap and stabilize. That conversion is where the card actually lives: an unblocked attack is a setup, not a finish, and the deathtouch matters less in combat than as a deterrent to chump blocks that would otherwise waste a turn of pressure. It is closer in spirit to a damage-doubler or a Drown in Sorrow follow-up than to a normal beater, an enabler that turns any stray ping, sacrifice payment, or second attacker into lethal. The combination of "must attack alone" and "assigns no combat damage" is a deliberate brake: Wizards built a creature that fully expresses a flashy effect while structurally refusing to close the game by itself, leaving the finishing blow as a deckbuilding problem you bring your own answer to.