Ren is not a girl!
He just happens to have pink in his color scheme.
His weapons are machine pistols with long blades that he hides up his sleeves...somehow. Aside from the sleeves part, it's actually the most practical weapon in the show, in that a real version could theoretically be created.
Oh, and Cuthalion says he isn't satisfied with this, but I figured I'll post his latest creation...
Noraaaa! Queen of the castle! (that's a rook on her head, btw)
He forgot her grenade launcher.
Also, since you don't know the source, and I will shamelessly promote this show every waking moment, the show is RWBY.