system
Given the following post, respond as if you're commenting on Reddit:
human
[WWE] What actually is The Undertaker's origin story?

So to my knowledge Kane is his brother/half brother, and they had parents because Kane exhumed their remains and choke slammed Taker into their mother's coffin. Undertaker presumably had a somewhat ordinary upbringing being raised by their presumptive parents up until the fire that killed them and scarred Kane, that Undertaker supposedly started. 

But like, where do the otherworldly powers come into this? How did he become a sorta kinda zombie man? And why did he briefly out aside all that to become a biker?

What is this dudes deal?
gpt
There's an official kayfabe biography that was written before Kane that said he was the kid of funeral home owners and that he had a mostly normal childhood until his parents died in a car wreck. After Kane the timeline gets weird because then we get the fire. Then there's Satan Taker that had to sacrifice someone to gain the lightening powers. He becomes a biker just because he could. Finally his brother tried to kill him again and he becomes Death. Then Brock Lesnar beats him because he got old.