Astrea Northwind

+1: Add two mana of any one color to your mana pool. Spend this mana only to cast creature spells.
0: Astrea Northwind becomes a 3/3 Elf warrior with "Whenever this creature deals damage to a player, draw cards equal to the damage dealt".
-5: Reveal the top ten cards of your library, put onto the battlefield all creature cards among them. Give them haste and trample.