Domineering Will

Borrowing a single creature for a turn is an old trick; conscripting three untapped blockers and forcing them into a wall is a different kind of weapon, and the design hinge is the phrase "target player." Read it as a steal and you misfire. The lethal line points the spell at the opponent: they keep control of their own three creatures, the spell untaps them, the mandatory-block clause then compels those creatures to defend, and they fall in front of an attack built to outclass them. No removal touches the battlefield; the army dies blocking the swing it was meant to stop. The reason the opponent has to be the target player is structural: a player cannot make their own creatures block their own attackers, so the slaughter only works when the bodies stay on the defending side. The "nonattacking" restriction is the limiter that keeps this from rerouting a combat already underway: it cannot grab creatures committed to an attack, so it operates in the pre-blocks window, conscripting defenders rather than unwinding an offense in progress. Pointing it at yourself is the lesser mode, a temporary three-creature loan to bolster your own defense or steal a profitable block; the loaned bodies can even attack if you cast the spell before you declare attackers and the creatures can legally swing, though the untap-and-block wording is built for defense, not offense. The kill runs through giving the defender no choice about whose attack they wall. Three short clauses cooperate, none of them destroys anything, and together they convert a defensive board into a graveyard.