Aethex Prime Conqueror

Menace
Other stonekin creatures you control gain +1/+1 and menace.
When Aethex Prime Conqueror attacks, look at the top 6 cards of your library, put up to 1 creature from among them onto the battlefield. If that creature is a stonekin, you may have it enter tapped and attacking. Put the rest in the bottom of your library in random order.