Aasimar, Monsters' Companion

{u}{r}{g}: Monstrosity 1.
Monstrosity abilities of creatures you control cost
{x} less to activate, where X is the number of
+1/+1 counters on Aasimar, Monsters'
Companion.
At the beginning of your upkeep, any number of
target Monstrous creatures you control are no
longer Monstrous.