Gray Fox:
1. I think that Gray Fox’ speed and reflexes are better than Raiden’s
2. Gray Fox is very strong (he lifted the leg of Metal Gear REX on his own and crushed a wall by slamming a soldier against it)
3. Gray Fox almost destroyed Metal Gear REX on his own
4. Gray Fox has more battle-experience than Raiden
5. Gray Fox is better at CQC
6. Gray Fox could kill anyone without showing any mercy, I think Raiden couldn’t do that
7. Gray Fox has that blaster on his arm and he has stealth camo
8. I think that Gray Fox’ suit is actually stronger than Raiden’s because Metal Gear REX slammed Gray Fox against a wall and the suit was still not destroyed while Vamp just pushed a knife into Raiden’s body without any trouble
9. Gray Fox has had better training than Raiden
10. he can reflect bullets with his sword or even cut them in half

Raiden:
1. Raiden is probably stronger than Gray Fox cause he stopped a moving submarine
2. Raiden killed Vamp
3. Raiden could kill hundreds of Gekko’s without stopping
4. Raiden is better with his sword than Gray Fox (I think)
5. Raiden just keeps going on while he’s losing body-parts all the time

Both:
1. they keep saving Snake’s ass all the time
2. they are very fast and have some amazing ninja-moves
3. they are very strong
4. they’re good with a sword
5. they’re both good at destroying things and killing people
6. they were both child soldiers

The Fight:
I think Gray Fox would win because he has stealth, a blaster, an almost undestroyable exoskeleton, more battle experience, he can reflect bullets with his sword and he has better reflexes than Raiden

if it would be the old Gray Fox (before he died and resurrected) he would still win this fight because he just has much more battle experience, he’s better at CQC, he had better training than Raiden and he could kill without showing any mercy

They both have roughly the same movement speed, strength favors Raiden a little pit, but Fox’s attack speed is so far greater than Raiden that it will be impossible for Raiden to block or counter it. It doesn’t help that Fox is the only one with a gun here so he gets to set the distance of the fight too.

Then there is the fact that Fox can actively dodge bullets marking him as a bullet timer (that isn’t just moving in such a way that bullets are unlikely to hit him, but actually seeing a bullet moving and then moving out of its path), and Raiden doesn’t have that feat as far as I’m aware, so Fox has a reflex edge on Raiden.

Raiden is more interesting to watch, but only for the fact that you can see what he is doing. Fox will seriously dismember Raiden so fast that not even Raiden’s near indestructibility will save him. He would be ribbons far too quickly for them to make a differance.