Klaus didn't panic after reading the description, despite knowing he couldn't kill his next target using his weapons or skills. It was as though he was heading into his next battle unprepared, yet he felt ready.
"So this will be a battle of wits," Klaus muttered.
He could already tell the battle would involve deciphering the true nature of the music she would play and uncovering what compelled her to create such a benevolent tune with a malevolent intent.
The description portrayed her as a victim, making Klaus recall a moment from his past life when he killed the Flame Dragon to gain access to the ancestral grounds of the Chaos Flame Demon Dragons.
Back then, that dragon was far more perceptive than his friends, and Klaus had been forced to kill him. But it was only after the act that he discovered the dragon was one of the few genuinely good demons.