Twilight Sparkle

Twilight Sparkle costs {1} less to cast for each
pony you control.
{3}: All ponies you control gain indestructible
until end of combat.
{10}{t}: If you control Elements of harmony,
Rainbow Dash, Pinkie Pie, Applejack, Rarity,
and, Fluttershy, and they are all untapped,
you win the game.