Kötücül's Ruins

Kotucul's Ruins enters the battlefield with one depletion counter on it.
{t}, Remove a depletion counter from Kotucul's
Ruins: Add {b}{b}{b}{b}. Use this mana only to cast Kotucul, End of Man
"Kotucul's Return is inevitable, may these
ruins serve as the reminder." - Kotucul's Disciple