Time for some fun

Akira bit his arm off 
(Precision strike))
30 billion stamina =10 billion unavoidable damage

Kobushi's arm fell off and he fainted.
Zero looked at Kobushi and then had Kabuto reattach his arm, "So, your really not going to do any thing about her?"

"I may have moved her towards your son. For being a prick."

"He can be at times. any who, lets get this training started." Zero said excitedly.

Riza pulled out a sword.

Zero held his Katana at the ready, as a child he had often studied swords so he was familiar with the katana. Kabuto held his great sword with both hands.

Riza, generally considered to he the best bladesman in The universe, easily bypassed both and poked the with his blade. "Precision."

Zero and Kabuto felt Riza stab them and looked down to see a small gash from the sword, "Damn." Zero exclamed.

"Power an speed mean nothing compared to technique."

"what do you mean?"

"Right now, use all your ability to block me, a combatant who is much weaker. No abilities or anything. Just your own power."

Zero readied himself with the katana. Kabuto held up the greatsword in a defensive position.

"Don't use the sword. You aren't trained with it and it will hinder your defenses."

"Fine," Zero put the katana away. Kabuto did the same.

"Bring your power to its max."

Zero used ever bit of his power. Kobushi was only able produce a fourth of Zero's power.

"Transformations too."

Zero used kaio ken times three. PL: 3,975,000,000
Kabuto powered up. PL:75,000,000

Riza charged.

Zero jumped over Riza and Kabuto jumped out of the way.

Riza, who had used the charge as a feint, suddenly reversed his grip on the blade and slashed them both easily

Zero and Kabuto were knocked back, "Crap."

"See? Even when I am clearly much weaker I can still hit you easily."

Zero got up, "I see what you mean."