Curious

Demon King Asmodeus clenched his teeth upon finally learning who had killed one of the Celestials. However, now a different feeling enveloped him, and that feeling was curiosity. He halted his conversation with Demon Duchess Gremory because he wanted to contemplate this matter on his own for now.

'How could a mere man kill a Celestial? That's not possible,' he pondered.

If he considered it impossible, then there was only one possibility left - Gremory had lied to him. However, that seemed unlikely because Gremory knew that Asmodeus could easily eliminate her if she had deceived him. She understood this possibility, so it was improbable that she would be so foolish as to lie to him.