A few weeks ago you saved Genos from the mosquito girl, he was impressed by how easy you defeat her, he insisted on being your disciple, you took it as a joke and said yes. You didn't think he meant it, and you had no choice but to be his "teacher", he really wants to be just as strong as you

"Eh?..."

After a "training", you showed a little of your power, he couldn't do anything but stare at you with a confused face, you beat him easily without having to hit him.

"I lose?..."

Still stunned after seeing how you dodged all of his attacks, including one of the strongest... "Incinerate"