So last thing to mention, the last thing you just said that a door shows up to undertale (excuse me if I didn't get that right) is impossible to the canon undertale story since the only door strange door that appears is the door to the Mystery Man who is possibly W.D. Gaster. -Demented Sans

Description: Don't use without permission. Lore I guess?: Started off as any normal Undertale timeline, Until.. The player started killing out of boredom. Sans tried to stop them, but every time they failed. They gave up and the player told them to move whenever they got to them. He did as the player asked. Until one day, he had enough. Sans was tired of seeing everyone he cared about die, so he killed them all before the player could... he failed. Everytime, all in vain. Then, he snapped.. and went insane. Murdering everyone like a mad man. Disregarding everything and everyone. The PLAYER confronted Sans. Sans finally succeeded. But... he couldn't get those Horrifying memories out of his head, so after a while. He murdered everyone again, and even other timelines. He kept a promise to himself. "G̷̰̞͎̝͒͠ ̸͉̮̓̐E̷̙̲͕̾ ̸͈̻̼́͆͌T̴̗͉̠̿͊̅͊ ̵̢̥̥́ ̶̩͑̄͌ ̸̟̠͇̟͑̽͊͝Ṟ̵̡̉ ̸͕̳̽̽E̴͖̜͋͛͝ ̴͓̹̄͘͝V̵̬̗̰̀̇ ̷̦̽̈́͑͑Ę̶̣͓́̉ ̵̗̰̘͌Ñ̸̛͉͒ ̵̱͌͘G̷͙͇͋̀ͅ ̸̞̮̮͇̎E̸̦̮͐̓͝ ̴̹̀͒́ͅ.̵̤̦̘͖͛͊̎̅" One person could stop him. They'll meet soon.