He buffs with phoenix pyre, strength of gaia, summon earthpower, soul vortex and then either whatever buff is deemed most useful for the battle(iron will, personal luck, breath of winter, misform, quickness ect) or simply some sort of devastatingly powerful spell such as soul drain, shimmering fields or master enslave.
His fear is +10, his awe is +6, his resistances are S100%, F100%, C200% and P100%. His chill is 16, his fireshield is 16ap damage and his reinvigoration is 18(22 after summon earthpower).
Sure he is still vunerable to instant death, sure petrify could still kill him and sure I still loathe the spells infernal prison and claws of cocytus(oh look, my B1 mage can gather enough resources to destroy 8 SCs per game turn
) but i love this guy. Also, 22 reinvigoration, soul vortex and soul drain work very well with phoenix pyre.
edit: Apologies for the size, im new at this.