considering the fact that Monkey D garp is the one who captured Gol. D. rodger and how powerful he is why hasnt he been made an admiral by now because back in the marineford arc when akainu went to kill luffy, garp walked over and was about to kill akainu so sen goku stoped him and by the look of terror on his face it seems as though sen goku believed he must have been capable so that leads me to the question if admirals are simply the strongest marines why is garp not an admiral or why hasnt he been an admiral yet. or do all admirals need to be devil fruit users?