Seclusion

Dan already realized long ago that if he really wanna live longer and get stronger to step into a higher realm, Supreme talent was thoroughly fundamental for it to happen.

Thus, he didn't care if he had to play the good guy so he manage to get a hold of his last strand of hope. The reason is that his technique would never work if the other person didn't carry gratitude and respect for him.

It's like that he had to play the kind-hearted master or the good father. In Dan's train of thought. To get kid's respect and gratitude, playing nicely always works for them, cause they are naive and easy to fool.

And Dan for his good well wasn't even thinking about the kid's life and death. After thousands of years of cultivation, and reaching the pinnacle of his current world. He stopped feeling anything after killing humans, for him, humans weren't any different than the grass itself.