I think that 9S might be stronger than 2B. In one boss battle on Route C, he single-handedly beats a bunch of clones of 2B. If that doesn't say he's stronger if he could beat multiple 2Bs, I don't know what does!
This is really good! I like the direction you've taken your art in! Also read the description and I wish I could help you but I don't think I would be the best person to ask considering the state I'm in over Yuri on ice XD
I'm obsessed with NieR Automata also. @ 3@ I thought I was obsessed with Horizon Zero Dawn... until I played NieR. My god that game is fun. I love 2B and 9S sooooo much!!! It would be awesome if you drew them together!! >3<