Prismatic Mox

{t}: Add {w}. Activate only if Prismatic Mox has
no charge counters. Add a charge counter.
{t}: Add {u}. Activate only if Prismatic Mox has
one charge counter. Add a charge counter.
{t}: Add {b}. Activate only if Prismatic Mox has
two charge counters. Add a charge counter.
{t}: Add {g}. Activate only if Prismatic Mox has
three charge counters. Add a charge counter.
{t}: Add {r}. Activate only if Prismatic Mox has
four or more charge counters. Remove all counters.