"I am the Wandering Demon, Rouge of the Warmester Denoble House," Rouge said as he raised the sword of light on his hand.
This sword of light was the very symbol of the Wandering Demon, which is him.
In other words, this would prove his identity to Raya Pazier, who was showing clear doubts that he was indeed the Wandering Demon.
And it seems that it was working as when Raya Pazier laid eyes on the shining sword on his hand, Raya Pazier couldn't help but doubt her eyes.
After all, it was absolutely unthinkable for the Wandering Demon, also known as the Dog-In-Leash of the Warmester Denoble House, to betray the Warmester Denoble House!
His pure loyalty to the Warmester Denoble House made the other demons fear him, even the other Denoble Houses were wary of the Wandering Demon, one of those Denoble Houses is the Pazier Denoble House, which is how Raya Pazier knew of the Wandering Demon.