Get Unscythe out, then when you have the mana available, use Magnetic Theft to attach it to your opponent's best creature, followed by Alpha Brawl at the same creature.

Since Magnetic Theft does not change control of the Unscythe, you control the triggered death ability.

Opponent's creatures are all dead and all but the one holding the scythe get exiled and hand you a token on the way out the door.