In my attempt to get Gilgamesh & Amakusa Shirou, I ended up NP5 Robinhood, NP1 Billy the Kid (should have NP2 but burnt him once when I was a noob) and finally, Archer of Inferno. (You can imagine the amount of salt with those back-to-back archers and no Gil!)
Anyway, I heard there is 400K HP SAlter in upcoming Christmas 3. According to Gamepress page, Archer of Inferno seems to be great ST damage dealer. Should I pour 101 embers I currently have (and farm more) to her? I think I already had all the ascension material for her.