Demonologist "Erupting Darkness" skill not obeying own limit

[PurpleXVI]

While it claims that it will only produce "1 volcano" in a pool within a given radius, I've had it produce up to 4 in one use. I do not think that is working as intended.

[Red]

If you have it make a volcano on spell proc, then it can produce volcanoes from its own damage. Other than that, no idea.