Calixe679 says:

Though, it is still a possibility that Add is Glave(not saying he is), which i’m referring to a couple of things: First the image seen in Eltype comic Henir’s Time & Space pg. 7 (http://en.elswordonline.com/henirs-time-space/manga.php) where Glave’s story involved with his past showing an image of a woman, and a dark figure of himself with his left eye gleaming. It closely resembles the new teaser picture of Add’s new class which also has a woman which could be Add’s mother(http://elwiki.net/w/File:Addteaser3rd22.png) while including in the picture has him covering his left eye (http://elwiki.net/w/File:Add3rdteaser.png). Second, “I can’t quite put my hand on that person. I can’t remember who he is…it’s frustrating…Lingering memories bother me, especially on a day like today…I woke up from a pleasant dream but I feel a sense of frustration because I just can’t quite remember what the dream was about… – Glave” this appeared as a description on a Skill Note for the skill Photon Flash, Eve’s skill, coincidence? imo, it feels like Glave was talking about his younger self before he became the administer of HT&S. We all know about Add’s obsession with Eve is 2nd to none, so seeing how Glave wrote this skill note just for Eve makes it a good possibility that Add will become Glave in the future having his memories messed up in HT&S. Third(not really) includes Add’s new class name “Time Tracer”, of course most people believe that he’ll be part of HT&S and I also believe that as well. Forth, for being in HT&S for too long, Ruto has his features change drastically from his skin turning blue, his eyes turning red, and his pupils being light blue. Probably the same thing is now happening to Glave, can’t really tell due to him wearing his mask and gloves. But the remaining feature that connects Add with both Glave and Ruto is that they all have white hair.This is just a theory but here’s what I think. HT&S alters Time and Space no matter what, so maybe due to some circumstances Add wants to travel to the past to be reacquainted with his mother before before the extermination of his family so he entered HT&S to get answers on how to. Though the Creator of HT&S, the God Henir himself, was displeased with Add making use of time and space for his bidding so as punishment the Creator locked a memory of Add’s past. Add being very persistent with his search, most of his memories were being locked away one by one, then sooner or later lost his mind not knowing who he is or what was his objective. Thus Henir gave him the responsibility of guarding time and space, the new administer Glave. In time, Glave met the elgang in a dimension when his memories started to spark once he saw Eve and/or Add. He then began to think to himself about his past and pursued it once more to find out and learn the truth about himself only meeting with Henir as a result. Infuriated, Henir sentenced him as a permanent admin having the cycle of time repeat itself. With age, Glave found that it was hopeless to go back to who he was and changed his persona to Ruto/Luto meeting the Elgang again with a strange yet a friendly smile and his odd chuckle like a certain someone.