The guide i made 3 or 4 days ago was really incomplete, so after a bit of testing new stuff on the boss i found a consitant way to kill him on 2:40 or 2:10 minutes. This is the strat, equip fast hold gloves and a golden erring for Ed and for Al equip dog collar and bullet of faith, when you enter the bossfight don't go for him let him come to you and transmute the cannon behind you and that is all the positioning, ill you the rest on a video.