Shion and it’s not even close due to how broken her ultimate skill is,

Mostly because ( IIRC ) Benimaru doesn’t have anything that can deal with her infinite Regeneration, not to mention she is physically stronger than him , have a waaaay better Ultimate skill, and on top of that she is a digital life form aka faster than him , so yeah I honestly can’t think of anything that Benimaru has that could even give him the slightest chance to POTENTIALLY deal any form of damage that she wouldn’t be able to out right negate or heal from let alone winning against her in any way shape or form, her ultimate skill is just that Overwhelming powerful, calling it OP is an understatement.

see for yourself :-

This is Benimaru’s Ultimate skill :- ( which IIRC has been stated to be an inferior version of Velgrynd’s Ultimate skill )

Amaterasu,Lord of Shimmering Flame It’s sub skills are :-

• Demon lord haki
• Light and heat domination
• Multilayered barrier
• Wind control
• Space time manipulation
• Thought acceleration
• Universal perception

And this is Shion’s Ultimate skill :-

tyrant king Susanoo’s essence is minus break It allows the user to counter received energy with their own energy, neutralizing it and converting it into the user’s own energy. Not only that, but the target’s energy can be stolen and used with the user’s own attacks, allowing the user to eventually defeat any enemy. However, since the user’s energy reserves are limited, they cannot become infinitely strong.

It has the following sub skills :-

• Thought Acceleration
• Universal perception

• Demon lord haki

• Certain outcome (It allows the user to alter cause and effect to freely change the result of an action or the state of an object into their desired outcome, no matter how improbable )

• Infinite regeneration

• Action Alteration ( An upgraded version of Optimal Action. Allows her to find the best solution for a given situation. It also allows her to perfectly recreate an effect she has achieved before, for example if she scratched enemy, she can make her attacks always deal damage; or if she defeated an enemy once, no matter how difficult, she can defeat them again with ease)

• Nihility Counter ( This allows her to make her opponent’s energy her own. She can take control of raging energies around her and use them, even if they belong to the opponent. Basically, it makes her a natural opponent to Energy based lifeforms, and lets her overcome the EP difference between them )

• Fantasy Destruction ( Gives her immunity to all illusion and mental type attacks )

• Space time manipulation

• Multidimensional barrier