[There is much about his originating world that would seem really strange to others, though there is a remarkably simple explanation for it. As for the questions being tossed this way... well. Serph answers in a flat, even tone, describing things in a dispassionate voice.]

We were told the requirements. Conquer all tribes by slaying the other leaders and bring the black haired girl to Sahasrara.

[Which. He knows now that black hair isn't exactly an uncommon feature in people. But it certainly was unique at the time! What value is a Nirvana that is reached through slaughter, though? Still, it had been their only way forward so that's what they did.

As for proof of rebirth...]

I've seen the Sea of Milk. It recycles the information of the dead [There was a computer console and everything!] so it was filled with incomplete humans.

[It was weird and gross seeing exactly the process that made him. Watching the human slurry go around and around was disturbing.]

When the process is complete, they are born with the rain.

[that sure is a weird human lifecycle huh]