Serious
Khan wasn't only fast. Achieving complete mastery of the Lightning-Demon style had made his attacks untraceable. No one could notice when he began sprinting, meaning that Tlexicpalli had seen him coming.
The level difference could explain that outcome, but Khan's body had several advantages. Moreover, he had steadily trained in the recent period, increasing his attunement with mana. He should have more than compensated for his lower standing, but Tlexicpalli had reacted to his sprint anyway.
The urge to smile tried to take control of Khan's face, but his expression remained cold. Truth be told, he enjoyed those friendly fights, especially against an opponent who could provide a challenge. The opportunities to test his power without needing to kill anyone were also rare, so he felt glad Tlexicpalli could push him to his limits.