Vega
He was about to answer Sethrol when Nanako asked something curious. For a moment, he cocked his head, hand resting on his cheek as if he were wondering something. A set of gorgeous aloof eyes stared right at Nanako, even as he looked puzzled as ever.
"Hrm? Did I do that?"
He strikes his hair back simply and gave her a shrug.
"I swear, you're such an oddball Nanako, getting heated like that! I mean, who cares right?" Sure he understood why someone like Sethrol would be upset, but why would Nanako care if the guy was dead or not? It's not like that meathead was complaining. Being a corpse helps there. "And I'm aware of that, old man. I am a superior existence, but that doesn't mean I'm the best version of me."
He paused for a second, almost giving Sethrol a more... considerate look. If you didn't know Vega, you'd almost think he respected the senile husk.
"I suppose I'll tell you one thing. It's only fair, you were the boy's teacher." He pulled out a rose and started toying with it, gently. Lovingly. "That fight was a consensual one, over the right to grasp your secrets. That... chi. It's the one thing you possess that I don't have. But I say, I've earned it by rights, haven't I? Being taught your power, those were the terms of the fight."
Until his fist crushed the flower, scattering the untouched petals into the winds. "You wouldn't trample on those scopes, would you? I understand you hate me, I can assure you the feeling is mutual. But that boy did deny my existence as much as I desired to enrich it. What happened happened, but it doesn't seem fair to deny the scope of the rules."
The boy's death would be quite pointless otherwise.