Diavolo was under immense pressure, having received numerous reports from RAD students or other demons in devildom about a strange figure who would randomly appear in the colosseum crying, singing or would just be standing motionless.

While Diavolo was tired of doing paperwork and exhausted from dealing with the 7 demon brothers, he begrudgingly went to investigate the colosseum.

So now Diavolo arrived at the colosseum in the dead of night, the moon shined brightly like any other night. Making it easier for Diavolo to see the path that led to the colosseum.

Although the tranquility of the night would end abruptly as the sound of a singing voice echoes throughout the colosseum. Diavolo silently entered, being cautious as to not make any noise.

He peeked out from behind one of the pillars to see a human? angel? demon? Or whoever, it was standing in the center singing. Although from this distance Diavolo could assume the figure was male, after all it had a sonorous voice yet a crazy vocal range.

It was a breathtaking sight as the figure moved elegantly while it sang it's- most likely hypothetical— heart out. They were truly alluring to see and hear.

As the figure kept singing Diavolo realized what song it was singing, he's heard of it before from Solomon after the sorcerer recommended that he'd try listening to human music.

If he could recall correctly the song being sung is Lamento Della Ninfa, a magnificent song with a tragic story about a nymph who was lamenting after being abandoned by it's lover..