Ruthless Warmaster

When Ruthless Warmaster enters the battlefield, create a 1/1 white Warrior creature token.
Dash—{b}, Sacrifice a creature. (You may cast this
spell for its dash cost. If you do, it gains haste, and it's returned from the battlefield to its owner's hand at the beginning of the next end step.)
You may cast Ruthless Warmaster from your graveyard using its dash ability.