Unstable Volcano

({t}: Add {r}.)
Unstable Volcano enters the battlefield tapped.
Whenever you cast a spell, put a pressure counter on Unstable Volcano.
{r}{r}{r}{r}{r}, {t}, sacrifice Unstable Volcano: Unstable Volcano deals 3 damage to each creature, planeswalker and player. Activate this ability only if there are ten or more pressure counters on Unstable Volcano.