ok lets look at what they both have and what they both are capable of.
mc: overshield, titanium armor, an arsanal of weapons (available), good aim good fighter, increadible strength, and i cant think of anything else.
gf: an exoskeletin, cybornetic implants, high frequency sword (makes it realy realy hot), is so fast he can diflect bullets with his sword, possibly even stonger than mc, can turn invisible, has a plasma canon.
ok with that what would happen is mc would know where gf is cuz of the radar but even so how do you shoot something that you can barely see and it moves that fast, then gf will come up hit his shield, then notising its strength retreats, then shoots him a couple times with his plasma canon until his shield is down then cuts his head off, but if mc had the bubble shield thing available gf would just go in and just keep hiting him while dodging all the bullets mc shoots at him untill the shield is gone and then finnish him off (also gf was almost as fast as he is in mgs before he became a cyborg)