I have composed a list of arguments in favor of a new arm for Yang because I don't want her 1 armed forever, and it's scaring me some people are in favor of that.
- She'd be vulnerable in a fight. Not only would she not have anything to quickly follow up after a punch but a martial artist could tear out her throat, arteries, and windpipes from her neck. a maneuver only block-able with both arms and more. Her semblance helps her grow in strength but doesn't do anything for defense.
- Using only one gauntlet will always result in launching into a corkscrew which would result in vertigo and vomiting
- Fighting with only 1 arm will only make her impact in a fight only 50% as effective than having both arms.
- She lost her right hand which is also her dominant hand
- She wouldn't be able to ride her motorcycle properly, steering would be more difficult and she'd even fall off. Especially on the fact that Bumblebee is a sports motorcycle and most motorcycles don't have seat belts.
- When she said "It's all gone" to Ruby, she shows the stub of her arm to Ruby despite the lack of verbal mention of that problem.
- Remnant Has the technology to make fully functional cyborg limbs. Look at Mercury, Ironwood and Dr. Merlot
- The following outside of RWBY lost an arm but have had theirs restored or replaced: Edward Elric, Guts, Big Boss, Raiden, Finn, and Maytag.