Michael

Hexproof
When Michael comes to the battlefield, put X
1/1 artifact creature tokens in play.
{t}, sacrifice X artifact creatures: Gain control of
target artifact with converted mana cost of X
or less.
{x},{t}: Put X 1/1 artifact creature token in play.
When Michael goes to the graveyard from play,
return ir to its owner library. Destroy all artifact creatures you control