[Transplanted from my comment in post #926688]
This seems to be part of some new Pixiv meme, tagged "BOX戦闘少女", BOX Sentou Shoujo. post #926067, post #926336 and post #926692 were also tagged with it. Seems to be original character designs though (judging by the オリジナル tag), so... pool it? copy:Tag it?
Updated by psich