There is also reforging process that would make your weapon rank/rarity a higher one, I think you should be at level 33 or higher to unlock that.
I am playing at xynete server, 2nd server. Avatar name is curimao, because any word that has "fu" can't be granted, prohibit filter in game I guess.
Always use the free auto raid at elite instance on the stages you already completed in case you ran out of stamina. It's on the lower left of the screen.