User blog comment:Water Dragon Slayer/Chapter 346: The Law of Regression/@comment-11966702-20130802162310/@comment-7418318-20130802162738

Over in FairyRaven's Review NatsuHime and me theorized that it might be Phoenix Grave.

The only thing that is know about that guild is the name and a single member who was mentioned in the weekly sorcerer (particularly the "Wizard I want as my boyfriend" column).

But the symbol might match up with the name, with it showing a G with flames around it. The G also could also double as the side-view of a bird.