Double strike (This creature deals both first-strike and regular combat damage.) Vigilance (Attacking doesn't cause this creature to tap.) Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)

As an additional cost to cast this spell, sacrifice a creature. Search your library for a creature card with mana value X or less, where X is 2 plus the sacrificed creature's mana value. Put that card onto the battlefield, then shuffle. Exile Eldritch Evolution.