Heimdall, Planar Attendant

Choose a color before the game begins.
Heimdall, Planar Attendant is the chosen color.
{t}: Add one mana of the chosen color to your
mana pool.
{t}, Pay 5 life, Exile Heimdall, Planar Attendant:
Other commanders you own cost {2} less to cast
until end of turn.
Partner