Shimmerhelm Falls

When Shimmerhelm Falls enters the battlefield,
put three time counters on it. Remove one at
each of your upkeeps. If Shimmerhelm Falls
reaches zero time counters, sacrifice it.
{t}: Add {w}, {u}, {b}, {r}, {g}, or {c} to your mana
pool.
{2}{t}: Put three time counters onto
Shimmerhelm Falls.