Skills Needed In order to use this.
Lava Arrows
Glyph of Immolation
With this you can quickly set everyone near you on fire and spam this continualy.
I never actually tried this. Can someone tell me how it works.
Burning Slinger (Idea)
Lint
Winterclaw
According to wiki, GoI is bugged such that burning doesn't happen on multi-target spells. For lava arrows, only your target is set on fire and not the ones near him.
Dr Strangelove
Just use rodgort's invocation. Everything is burning AND mostly dead.
Darkpower Alchemist
GoI is best used on targets that are individualized, such as a GoI+Mindblast+Steam scenario.