Flashy name for nearby guild mates

[Xrystal]

You might want to have a look at how the person created this one and see if you can add guild related checks to modify similar items to your specifications.

https://www.wowinterface.com/downloa...ameplates.html

If you are not knowledgeable enough to do this yourself then if you ask nicely the developer of that addon may add a guildie option to their addon.