>>150035326
Ruby can counter a lot of Maka's arsenal, particularly being able to outright depower Maka by disarming her, severing her Resonance with Soul, which removes her ability to utilize her Black Blood as well as all of her Resonance techniques. She can do this very easily with her Semblance which breaks down matter on an atomic level and reduces it to a cloud of scattered particles she can move around. She can also bypass the defenses of the Black Blood with her Aura-enhanced strikes in the same way that theSoul Menacetechnique does in Soul Eater.
Ruby can also sustain herself for a lot longer than Maka can, having the stamina to fight for days on end before needing rest and having multiple pieces of equipment that heal herself and restore her Aura at will.
The only major advantages Maka has over Ruby are regeneration and Madness. The former would be able to help her against some major injuries but wouldnt heal her from decapitation or bisection, the two main ways Ruby kills her opponents. The latter would work on Ruby but is a double-edged sword that can also backfire onto Maka as well and potentially turn Soul against her, and theres an argument to be made that Ruby would be able to resist it due to her resistances demonstrated against the Apathy and Nightmare.
Theres also an argument that can be made about the Silver Eyes harming Maka due to her having Madness of Black Blood embedded in her body, which would potentially harm her for the same reason as Cinder due to an arguable similarity between Grimm and Madness, both being abstract manifestations of the negative emotions of humanity, but this argument is a stretch and is unlikely to be used.
So yeah, Ruby should take this high difficulty.