#'''Molten Infusion:''' 3+ to be answered, pick a magmic invocation within 12" of the priest, do not make a temperamental nature roll for that invocation. Not bad, but you are sacrificing some useful prayers.
#'''Searing Heat:''' 3+ to be answered, pick an enemy unit within 18" of the priest, it gets -1 to hit until your next hero phase. If you have multiple Priests, pick it. If you have only one Priest, there are better options.
#'''Prayer of Ash:''' 4+ to be answered, a friendly unit wholly within 18' of the priest gets +1 save until your next hero phase. By far our best prayer, always try to put the priest within 18" of the forge to have it on 3+.
#'''Ember Storm:''' 3+ to be answered, a friendly unit of Vulkite Berzerkers or Hearthguard Berzerkers wholly within 18" of this priest can run and charge. More mobility is always good, but once again, there are better options. If you have multiple Priests and an infantry-centered list, pick it. If not, picking Prayer of Ash first would probably be a good idea.
#'''Prayer of Grimnir's Fury:''' 3+ to be answered, a friendly hero not mounted on a magmadroth within 12" of this priest and 3" of an enemy unit can pile in and attack with all its melee weapons. Weirdly this does not specify Fyreslayer hero despite the magmadroth stipulation. Have fun with allies (Gotrek, a Celestant-Prime, etc) or your Grimwrath Berzerker.