Well Asuna can't really win here, since you know, she can't really do much outside of the game. So it is between Akame and Kagura. Yeah Kagura is really fast and knows gravitational magic, but let's be real here. Do you really think that she can beat a pro assassin that has a demon sword in her procession? Akame's sword will kill you with a single scratch. So do you see my point here? Akame will undoubtedly win against Asuna and Kagura.