Saitama and Genos enter the lair of the House of Evolution and find themselves in a large hallway. Genos mentions how he can sense many lifeforms in the compound, and two lifeforms coming towards them down the tunnel. Carnage Kabuto appears carrying Dr. Genus, who after telling Carnage Kabuto which of the two was Saitama gets thrown to the side. Carnage Kabuto then smashes Genos into the wall and continues down the hall until he is behind Saitama, leaving Genos embedded in the wall. Carnage Kabuto introduces himself to Saitama and tells him that there's a large nearby room where they can fight, Saitama agrees to follow on the grounds of Carnage Kabuto making Genos look like "modern art".
The two arrive in the room and the fight is about to start when a large blast of fire washes over Carnage Kabuto, that came from Genos who appears in the doorway. Genos then rushes at Carnage Kabuto and sends a barrage of punches his way, these have little to no effect on him as he simply punches Genos in the face and sends him bouncing off the ground and across the room only to be caught by Saitama. Saitama tries to get Genos to stop, but he lets out another blast at Carnage Kabuto, who simply takes a deep breath and uses his breath to blow the blast back at Genos, which then washes over him and makes his hair poof in the shape of an Afro. Saitama then steps in to fight with Dr. Genus watching from the doorway, and Carnage Kabuto mentions how he can feel that Saitama is very strong. Carnage Kabuto then, at blinding speeds, moves behind Saitama and is about to attack him when he senses Saitama's aura which causes him to jump back in fear, thinking that if he had attacked he would have been killed easily. Carnage Kabuto then yells at Saitama, asking him how he became so powerful. Saitama agrees to tell him and asks Genos to listen up as well.