Ok playing with the DPS sheets, I get Res slightly, very slightly ahead of Fire Magian Upheaval. Once you start uncapping accuracy though the GAXE pulls ahead due to it's 18 higher acc. Though resolution still does more WS damage the Fire GAXE has higher melee dps. Save TP / Monarchs and buffs favor the Jing Res over the Fire Upheaval.

Conclusion would be that a Jing Res setup would work as a good stand-in until he gets his Ukon. He doesn't have bother with building a Fire GAXE that'll be replaced with something far superior.