(The rivalry between The Undertaker & Kane spans many years. Many questions have been asked, here are my answers)
The Genesis of the Demons
"NO! YOU'RE...you're lying!", a young Mark declared. He had just heard the story for himself, he somehow had a little brother. Mark looked at his father, who couldn't bring his eyes to look at the woman he once loved. Shock fell on his face, the look in his father's eyes said it all. What his mother said, it was true. She cheated on her husband, his father, with a fat guy that stood outside shoveling Pringles in his mouth. "I'm sorry Mark, but please don't be upset. He's right outside, don't you want to meet him?", she asks him hopefully. All the lessons he had learned, the times he was scolded, the love he thought they had was nothing. Their family was gone. None of it mattered now. "Fuck you.", he said with a shaky voice before continuing, "I HATE YOU! YOU'RE NOTHING BUT LIARS! PIECES OF DISGUSTING SHIT! I want nothing to do with any of you.". He ran outside of the home they shared, determined to never go back. Of course, he did eventually. Things were never the same though.
The fat man, Paul Bearer, didn't come so Mark could meet him. He didn't show up so Mark could meet his half-brother. He came around because, in his eyes, he "couldn't" take care of his son. The reality was that he didn't care to look after little Glenn, that he thought there were more important things. That day, he showed up to dump Glenn with his mother & never look back. To Glenn it was a relief, with his father he was malnourished & lonely; not allowed to leave without permission that he almost never had. He saw this new home as a saving grace, while his new half-brother saw him as a hunk of trash.
Mark constantly picked on Glenn, bullying him & even at times being abusive toward him. Mark's father had checked out years earlier, when he discovered that the woman he loved betrayed him. At this point, he was constantly keeping himself busy with his work as a mortician. He became so obsessed with it that Mark & Glenn's mother moved them all into the funeral home he worked at just so he was forced to spend time with 'his' children. While Mark's father, at times, managed to show some signs of compassion & care towards his son; he never once looked at Glenn as anything more than a reminder of what his wife had done.
One day, in the midst of one of Mark's more abusive acts against his half-brother, Glenn struck back against Mark & cried out in a rage, "YOU THINK IT'S FINE TO TAKE YOUR SHIT OUT ON ME? TELL ME, WHAT THE FUCK DID I EVER DO TO YOU MARK? NOTHING, YET YOU FEEL THE NEED TO MAKE ME PAY FOR WHAT OUR MOTHER DID, & FOR WHAT? WHAT DOES IT DO FOR YOU? DOES IT HELP YOU FEEL BETTER? DOES IT HELP THE PAIN GO AWAY? TELL ME WHAT IT FUCKING DOES FOR YOU!". Mark stood there, looking at his younger half-brother; his brown hair caked in mud, leaves sticking out of it while his face is bright red in anger. As he looked at Glenn, he realized that he couldn't answer the question. He just stood there, looking at him silently. "Just as I thought. Mark, I'm sorry. I've tried to be understanding, I've taken your shit for years & the only person I've ever had for comfort is Mom. I refuse to take this abuse for one more day though, I can't do it anymore & I shouldn't have to.", Glenn states vehemently & with a shuddering, maddening breath. Mark looks at him, but says nothing before turning & walking away.
As their mother sat next to Glenn, cleaning his cuts & tending to his bruises, she says, "I know it's hard sweetie. It's hard for all of us, but it's probably harder for Mark than anybody else. Just remember, one of these days Mark will see past all the anger & realize that you're a good person.". Glenn jerks a little as she applies more antiseptic to a rather nasty cut the back of his neck before replying, "You say that every time Mom. I just don't understand why, why did this happen? Why do things have to be this way?". The mother puts her arms around Glenn & gives him a hug as she breaks down into tears, cries quickly turning to sobs as she admits, "It's all my fault sweetie. I did something stupid & made the lives of everybody I love miserable. Please... please forgive me son.". He hugs her back, comforting his mother as she sobs. For awhile, neither of them say a word, just sit there together.
Eventually though, Mark's father walked in & saw his estranged wife holding her love child. Something in him snapped, & he grabbed a pan that was sitting on the kitchen counter. After yelling out wordlessly, he bashed Glenn in the head with it. As Glenn's body slid to the floor, his mother jumped up & started yelling at the mortician. She saw there was no excuse for that, & they proceeded to fight as he wanted to continue to abuse the teenager who only a moment ago was hugging the woman he once loved. Mark heard the commotion, but didn't care. He just wanted silence, he wanted to get away from the pain & the drama. The noise started getting to him more, the chaos below him as his mother & father fought burned a hole in his brain until he couldn't handle it anymore. Mark became determined to stop it, by any means necessary.
However, Mark wasn't sure what to do. He knew if he barged in, he would surely get involved & that was the last thing he wanted. He just wanted it to stop, & as his eyes fell on 1 of his father's embalming tanks; Mark started to see what he felt was necessary, what he had to do. He went down to the basement, to where his father worked, & knocked over several tanks of embalming fluid. As Mark created his own chaos, the anarchy around him vanished from his mind. Soon canisters of various embalming chemicals were all over the "home", drenched into the rugs & leaking from the floors & ceilings. For the first time since all those years ago when Mark was told how his mother cheated, that she had a kid with another man who turned out to be a disgusting, manipulative bastard; he was at peace.
Mark left the funeral home, the smell of formaldehyde & glutaraldehyde heavy in his nostrils, & a darkened sense of peace was settled on his soul. There was only one way to stop the madness, to stop the grief & the pain. There was only one way in his mind, & he was determined to do it. Mark withdrew the matches he took from inside, & looked inside one last time before lighting the matches & throwing them inside. The house was set aflame quickly, even faster than expected due to the amount of chemicals soaked into the floors. Soon the shouts of anger turned into scream of fear as the flames had surrounded Mark's family.
Mark, he simply stood there, watching as the fire grew higher & hotter inside the remote funeral home. Soon, the screaming stopped, & all that was left was the loud crackling of the fire as it burned down the funeral home. He stepped closer, feeling the heat of the flames. Mark breathed, heard nothing but the sounds of crackling flame & the creatures of the night stirring. There was finally peace, the pain was gone. Relief washed over him, relaxing him so much he went to sleep right there next to the fire. A content smile was on Mark's face the entire night.
The next morning, Mark woke up with a blast of sunlight hitting his eyelids. For a moment, he thought it was all a sick dream. That was of course until he realized where he was, that he did in fact spend the night sleeping on the ground next to a burning funeral home. As he turned to face it, all Mark saw was a pile of ash & rubble. Thoughts raced through his head as he asked himself how this could have happened, wondering if he really did go that far. He quickly realized though that it wasn't a dream, that the reality was that he killed his family.
Mark then decided to at least give them a somewhat proper burial, after looking for something to dig with. He found a big spoon in the wreckage of where his kitchen once stood, & proceeded to dig a hole in the area they used to call the backyard. In the light of the warm, ever rising sun he toiled until finally it was deep enough to hold the remains of his parents. As Mark started to pull at their remains, he noticed an urn sitting on its side, practically untouched by the flames. It wasn't all that odd to him, since he lived in a funeral home, but what was strange was how it was virtually unharmed. Mark took it as a sign that he was meant to use it, & scooped up some of the ashes around his parents' bare skeletons, watching it fall into the urn. Lastly, he took the shriveled, dried up lumps that were once their hearts & dropped them inside the urn. As he searched for Glenn's remains, the urn stood, always in his line of sight. It stood as a reminder of what he did, a symbol of the guilt that plagues him so that he never forgets this moment, the extremes he went to instead of facing them like an adult. The relief he once felt turned into a mountain of guilt, one that he knew would never go away. It was something that would always have power over him.
He never found Glenn's remains, Mark just assumed he was burnt right down to the bone. It wouldn't be until years later that he knew the truth. On that day, the darkness inside Mark corrupted him, & The Undertaker was born. However, as we all know, that was the same day that the fires of hatred consumed Glenn. That same day was the day that Kane was born.