Overwhelming Pain

Just when Max thought he was done for and the demon king revealed a victorious smile, a water barrier enveloped him. 

When the demonic claw clashed against it, it shattered into pieces with a crisp 'Kacha' sound.

Phew!

Max exhaled in relief and muttered, "Thank you. I'll be sure to repay you for this."

After saying this, he swept his blurry gaze over the five demon kings before falling to his knees, unconscious.

Though he had physically completely recovered from all his injuries he suffered due to Alijah's attack a few hours ago, he mentally had not.

Then, the exhaustion of his intense workout with Lily and Sera piled up. Immediately after that he started fighting.

The fight with the first demon king had already exhausted him enough that his body and mind had started begging him to rest.