i dont think its a mecha arm i think its just part of there clothes but thats a real good theory about how the keyblades and the arm thing could be conected ^^ the reason why i dont think its a mecha arm is because ven has one and it only covers his shoulder and sleve not his whole arm. and i've been wondering about this for a while and i thought we've seen the color of terra's armor and keyblade and aqua's armor and keyblade. but what about ven because in the final mix/ and normal kh2 vid the color of there armor looked the same. but then i thought since terras arm thing that covers his arm looks exactly like his armor that must meen that the arm piece on ven's shoulder must be the color of his armor but idk what color his keyblade would be? im pretty sure that those are keyblades. just think of it like this: when they make an ipod it is good and all but when u drop it u could scrat it, break it, crack the screen etc. but when they make a newer version of an ipod it is advanced and is more durable than the older version. thats how keyblades must of been. in the past they weren't as durable as the keyblades are in sora's time. and this also fits in with the mecha arm theory (which is a good theory btw ^^). they might've needed that arm piece to summon there keyblades but as the years past the keyblades became more advanced and they eventually figured out how to summon a keyblade out of thin air instead of the arm thing. so what do u guys think?