Righteous Fire

One nice thing about RF burn being separate than Ignite burn is that they can both be applied to the same enemy. You can't stack multiple applications of the same burning type (they get added one after another, not at the same time). The ground burn from Fire Trap is also separate and different than Ignite or RF burn. So it's possible to hit an Enemy with a Fire Trap that crits and ignites the monster in addition to him burning while standing in the Ground fire. Add RF to the mix and that monster would die pretty fast, especially since the Fire Trap crit would be multiplied by RF's more spell damage multiplier. If you want to get really fancy, add in a Searing Bond Totem for a 4th burning type.