Alright, so from what I can tell, the other character in the image is an enemy called "dragoon" in girls frontline, and they're the ones riding the machine gun robots.

I have no idea how to do character tags, but I suppose just throwing it all under sangvis_ferri_android_(girls_frontline) is probably fine, unless that's a specific enemy, then someone who know more than I do should make the tag character tag dragoon_(girls_frontline), and throw this set of images under that.

Edit: And I also don't know if I should leave the character request tag up if I'm unsure, so if someone could let me know for the future, that'd be nice.

a new tag name called dragoon_(girls_frontline) should be made.

and this android unit need more love to.