Ruins of Lemuria

Ruins of Lemuria Comes into play tapped.
Ruins of Lemuria comes into play with 2 depletion counters on it.
{t} Add {u} or {r} to your mana pool.
{t} Remove a depletion counter from Ruins of Lemuria, add {u}{r} to your mana pool.
If there are no depletion counters on Ruins of Lemuria, sacrifice it.
Whenever you cast an instant or sorcery spell, you may untap Ruins of Lemuria.