Theon Greyjoy, Conflicted Son

When you cast Theon Greyjoy, place him on the battlefield of an opponent
During your opponent's upkeep, roll a die:
• 1: Your opponent draws a card
•2-3: Your opponent discards a card
•4-5: You discard a card
{bull}6: Theon Greyjoy attacks its current controller
and is unblockable