Cortana

A.I. (When this card is not enchanted to something, it becomes a creature with its power
and toughness equal to its converted mana cost).
{4}: Enchant target permanent.
If this card is enchanted to a vehicle, it is
considered crewed.
If Cortana is enchanted to a non-artifact creature,
it gets +1/+1, it that creature is The Master
Chief, it gets +2/+2 and Lifelink.