Gandalf the white

Vigilance, Lifelink, Partner with Gandalf the Grey
When Gandalf the white enters the battlefield, if you control no cards named Gandalf the Grey, exile Gandalf the white. If you do control a card named Gandalf the Grey, Destroy all creatures named the gandalf the grey after Gandalf the white enters the battlefield.
Whenever you cast a white spell, you gain 3 life
and draw a card.
You can cast Gandalf the white from Exile.