Sonic the Hedgehog

Sonic can't be blocked if he entered the battlefield this turn.
Dash: {r/w}{r/w}{r/w} (You may cast this spell for it's 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.)

Whenever Sonic deals combat damage to a player, create a Chaos Emerald token (It's an artifact with "{t}: add one mana of any color.)
{t}: Sacrifice 7 Chaos Emeralds to Exile Sonic the Hedgehog and return him to the battlefield transformed.