A 5-foot-diameter, 5-foot-tall cylindrical fountain of magma erupts from the ground in a space of your choice within range. A creature in that space takes 3d8 fire damage, or half as much damage with a successful Dexterity saving throw. A creature that enters the area on its turn or ends its turn there also takes 3d8 fire damage, or half as much damage with a successful Dexterity saving throw. A creature can take this damage only once per turn. A creature killed by this spell is reduced to ash.