I just thought of something.
DOUBLE IGNIS WITH +10 SPECIAL DAMAGE EACH PROC. (if foes can even last his first Ignis)
I can see him performing that Swordhardt build rather well, tho.
Also being infantry gives his access to the effects of Infantry Rush. Gives him the potential to constantly shoot off Moonbows/Glimmers with an ally with Infantry Rush.
But he's not unbeatable, like you said.