Oz Vessalius is a capable kid who did his best in trying to unravel the mysteries of the world. He can fight but he’s not ready for a battle hardened warrior like Kuroyukihime. She earned her title as one of the kings due to her unbelievable power. She can move faster than Oz would be able to capture with his eyesight and her attacks have a solid amount of piercing power. A single good hit would easily win her the match. Kuroyukihime wins.
Kaguya is a very capable strategist but she’s not going to be able to take down Oz. Oz is trained with the sword to an extent and has his contract with the B Rabbit. Kaguya’s archery can be a really good long range option to be sure but it’s not quite as good as the sword. Granted, in cases where you are really expert with the bow you can pull off the win but ultimately this isn’t that matchup. Oz Vessalius wins.