Rock of Eternity

Rock of Eternity comes into play tapped.
Whenever Rock of Eternity untaps put a charge counter on it.
As long as Rock of Eternity is untapped, Mystical creatures you control have flash and {2}: Regenerate.
{1},{t}: Add {x} to your mana pool, where {x} is the number of charge counters on Rock of Eternity.
{t}: Remove {x} charge counters from Rock of Eternity: Add {x} mana in any combination of colors to your mana pool. Rock of Eternity does not untap as normal next turn.