Arkan's Tesseract

{x}: Imprison target creature with converted mana cost X. (To imprison a creature, place this card over it, face up. It can't attack or block, it can't be the target of spells or abilities, and its activated abilities can't be activated.)
At the beginning of your upkeep, you may pay 5 life. If you do, creatures you control can attack from your graveyard and exile.
His greatest creation was also his last.