How good is Ravenous Earth's Foul Erruption in RR?

Tooltip says “slain foes”, I am guessing it applies after mob dies, or something? Does anyone have a definite answer to that?

Good in crucible

Good against foes who summon i.e Queen, Moose etc.
Useless against foes who don’t summon like Shar’Zul, Grava’Thul, Gabal’Thun etc.

It’s good when it goes off. The problem is that there are a lot of singular bosses and other challenges where it’s not going to go off. In practice, I prefer getting my RR from somewhere else, like Manticore.

Not worth investing in IMO, unreliable RR is just not attractive at all.
The skill is pretty good to proc devotions with though, especially those with no cooldown.

You can do some cool things like Ravenous Earth -> Flame Torrent/Twin Fangs for many procs, plus it reduces enemy damage by 25%.

Not realy good. Blade trap level of “good”.

1 point worth, If Ravenous earth itself actually kills stuff and is not just means for devotion proc.

yep, tested it on my defiler, even with full vita to fire conversion it kinda sucks.