Xathri, Statue Maker

{b},{t}: Put a petrification counter on target creature
you control other than Xathri. It gains defender, indestructible, and is a colorless artifact in addition
to its other types.

{g}{g},{t}: Creatures you control gain menace and
can attack as though they didn't have defender this
turn. Activate only if you control two or more
creatures with petrification counters.