Pherexes, the Reviled

Flying, menace
As long as you control no other creatures, Pherexes, the Reviled gets +3/+3 and has indestructible, lifelink, and "Whenever Pherexes attacks, you may discard a card. If you do, target creature gets -X/-X until end of turn, where X is that card's converted mana cost."
Discard three cards: Return Pherexes from your graveyard or exile to the battlefield.