[@Thecrash20]I was thinking more OPM's Genos, FMA's Ed, or DC's Cyborg than I was Pain for the weaponized arms. But like I said I think instead of doing that I'm going to go for just the arms themselves; MHA's superpowers have that uniquely Japanese concept of "learn one thing to do ten thousand" as opposed to the usual Western system of "just keep giving him more stuff." For instance, Superman's got separate powers of strength AND super-breath. All Might only has strength, but can use it to create shockwaves/gale force winds--without losing the nuance that it is CAUSED by his strength, and thus has to be done a little differently than someone who has aerokinesis.

Thus the Quirk "create mechanical arms" should probably be just that--They might be big arms, long arms, multiple arms, arms with an extra joint, but they won't be something that ISN'T an arm like cannons, blades, etc.

As for our ideas being so similar, if you're super set on your idea I can do something else.