You know it is possible beat him without switching controls. Thats how I did it. As a matter of fact the first two times that I beat that game I didnt even
know you could switch controls and beat him like that. I takes a little time to learn when you can hit and when you cant hit him. Use the Famas and attack him as soon as he finishes attacking (of couse you have to dodge the attack first) also when he disapears and you can also attack him at the very moment that he reapears. (But sometimes he stays still when he disapears and thats when you have to use your thermal g to find him.)
Also when takes controll of maryl after you knock here out he sometimes throws a disk like projectile if your quik enough you can attack him right before he thows it.
Trust me Im consider myself an expert at that game, it took me a while to find his pattern and finally beat him. But when i found out you could switch controls and beat him without any effort at all, You can bet that I felt like an idiot.
If you want to can send me the save game file Ill beat him for you.
PM me or just email it to me
[edit]
sorry hagbard i didnt see your post, I guess we were replying at the same time.