So I will not continue this novel and I drawled too much with all those motives and for those who wanted to see how it ends:
Volume 1: of Gilgamesh and build the mesopotamian world, beginning of his legend as a king and the conquest of a kingdom (a small one compared with his) but it would be a solo conquest so I the fight being awesome, and the beginning of a plot with his mother.
Volume 2: He that his "love" directed at his mother is and she refuses all of his advancements despite loving him as a mother, enraged after a he leaves his kingdom to vent his anger while having a metamorph familiar (one that was attacking some civilians some weeks after his and he dealt with him, turning him in with his op charisma) in his , he hunts some phantasmal monsters (he don't really need id dungeons in this age) he finds a huge cave and decides to explore it and after entering it the gamer shut down because of a quest and only his stats and quest can be seen, not having choice he explore and finds ea but has to pass one trial of resolve to be strong, he pass it and comes back to his kingdom but gives the cold shoulder to his mother and completely ignores her, having found a wife and having a kid (before ea and after it would have 2 major timeskip of him being a king and the other being a king and trying to his mother having (i was here to him conquering some kingdoms that worship other gods and seeing that the link between gods and humans being severed, the gods deciding to humble gilgamesh with enkidu, here the fight was easy (with him having so many stats bonus, go check "fate's newest gamer" I would use all of that, at this time his powers were warping reality and physics don't really work with him anymore so him being pushed back or flung away or him having moved a muscle when being hit and being tired didn't happens so even if he was losing hp he would look badass, and truth to be told he was nearly dying after 1 week of fight having lost 9/10 of his hp and enkidu as it/she was a construct of the gods she never tires and she has too a ability to always recuperating to full life when in touch with earth and using her almost infinite mana to regenerate so he uses ea and wins with enkidu losing her ability and the usage of mana being severed but he too don't leaves unscathed and falls in a crack, and realizing and his "final moments" remembering his life that he didn't truly loved his mother and his actual wife being a escape and that he liked being a good king to his people even if he became bored in the passing of the years and laughs remembering that he told his metamorph familiar the original legend of Gilgamesh and said to act like him even if a bit different if something happens and knowing but creating a legend and having suchlike tussle as a life he wishes to know true love once again living a normal life if he happens to have a third life
volume 3: in simple words is he being transported to artoria's age before she pulls caliburn and finds love with her with him giving tips in how to be king and all that shit that happens in the original don't happens but artoria to the world dies when se noticed she wasn't needed anymore and "retires" being with gilgamesh for the rest of the eternity (I don't really thought this far in the story but the shape it was meant to be it is this as the gamer powers would not be really important to the plot here) and at the end I was trolling saying that I would make a harem but the thought really crossed my mind but I wasn't really sure how to make a harem with artoria, a goddess (the one that created his armor) enkidu to be the fluffy eye candy that I originally wanted, his human wife and the hun so yeah
Oh, if someone wants to adopt the idea and want to make something to this story, it's all yours to do so!