Osmund Saddler

Eminence - All mutants cost {1} less to cast
{2}{b}{w}: Target creature is now a mutant (This
ability can be used multiple times per turn.)
{7}{b}{r}{w}: Take control of all mutants on the battlefield, they are untapped, and have haste.
At the end of your turn, if you control more
than 10 mutants, transform Osmund Saddler.