So, if they gave Ghorn an afterglow, how would you make it proc?

Weapons afterglow procs after using the relic WS which, on the most part, are rubbish. Aegis procs after using shield bash, which is on a 2:30 (if fully merited) timer. You could hardly get an afterglow just for singing!

Stuff like this always makes me laugh. There are jobs out there that are completely broken, and can't ever get to do decent content, yet jobs like MNK WHM BRD, which are guaranteed slots, complain that "I want new spells", "My kick attacks don't do enough damage" or "My horn doesn't have an afterglow and isn't getting +200 skill like all the other relics".