Well, Beyond could very well one-shot. The problem is that they are 70 meters apart, and Grave is only dozens of meters.
Not that it matters, with Slyfox's analytical prediction, he could very well dodge even if he got in Grave's gun range since many in the verse does that.
Now for skill, let's start with basic stuff.
First off, Slyfox is a Control Metahuman. A very good one, at that. For starters, normal
Control metahumans were able to perfectly control their bodies as well as any weapons they were wielding. These types of metahumans often preferred to use complicated technological weapons, such as various types of firearms
Secondly, he scales laughably above Cloudhawk in terms of gunskills, who was stated when he wielded his revolver for the first time, he felt as if his mind had reached out through his body and extended into the gun itself. He could clearly sense every tiny part and every molded line with perfect clarity, almost as though the revolver was part of his own body. It was like his eyes, his arms, or his legs;
he was able to control it with absolute mastery.
Cloudhawk, for one, can kill an Alpha rotwolf by headshotting it,
despite the Rotwolf itself being much faster and having analytical prediction in terms of instincts and can dodge bullets due to it.
Additionally, it was stated that Slyfox was able to use two modified pistols to hit bull’s-eyes from a hundred meters away
without even aiming[1] as well as capable of shooting and destroying Mad Dog's machetes
dozens of meters away without even looking.[2] It was also stated that he is capable of instantly locking onto and shoot even a falcon flying at top speed, and was able to shoot a sparrow from thirty meters away as easily as shooting an elephant. You know, Sparrow, the bird that is like, 14 cm in terms of length?
As for analytical prediction, well, I'll just repost the justification: Should be far superior to Cloudhawk, who is capable of predicting where the Alpha rotwolf will dodge, despite the rotwolf's sense of danger.
[1] Additionally, he's able to predict and shoot 4 bullets against Number Four,
making sure it was impossible to dodge, had it not been for Number Four being hilariously above Slyfox in both speed and strength, and being extremely precise as well[4] to the point it was stated his attacks were so precise as if he had measured them to a millimeter in advance, and all his moves were calculated countless times in advance before attacking and showing no weakness
[4].
Number Four was so much more powerful and skilled that he was able to predict where Slyfox will shoot even despite Slyfox covering his line of vision with a body so he cannot see the gun. However, Slyfox was eventually able to almost kill Number Four after he has watched his movements, his breathing, his every minor motion. After having taken all factors and possible responses into consideration, he was almost able to kill Number Four had it not been for the latter to increase his power and speed even more. It was even stated that Slyfox perfectly calculated his movements and all potential variables,
he had even taken into account Number Four's reaction speed and the speed at which his hands were able to move. Even Number Four stated that this shot had virtually sealed his fate, and stated he was a truly formidable gunner
Keep in mind that not only is Number Four laughably above Slyfox in terms of strength, but in speed as well. One key factor here is the fact that Slyfox calculates all potential variables, and especially his
Reaction Speed
Why does that matter? Well, Grave has a reaction speed amp. So when Slyfox shoots a few bullets, he'll be able to calculate his reaction speed due to the amp (Assuming grave can even dodge them) and just shoot perfect bullets so that Grave can't dodge.
Also, for starters, many dudes in the verse can be injured by bullets, even dudes who can destroy 2 buildings in one attack. So, it's safe to say that Slyfox can headshot Grave and can possibly immediately kill him.