I assume it's there for when the expansions come out, and then maybe you can get faction for a different god, and have to talk to their priests to unlock stuff (probably stuff from that expansion, as it were).
you gain faction from him through war, meaning pvp. You can use this faction to unlock upgrades, runes and skills at a "priest of balthazar" in the different PvP starting places (both the arenas and tombs of the primeval kings). Unlocking stuff makes it available for use with any of your pvp-only characters.