Undertale: The Altered Timeline (ATL!Sans)

Chapter 2: expedition through worlds

After he went back to the dark hallway through his save point sans felt a relief to see something familiar yet still new and mysterious. He processed everything that has happened so far ever since he went to that cursed reality, and in doing that a terrible shiver went down his spine and shook his body in an effort to shake the nerves off but he question, were those part of that reality or were they from others as he suspected and what could possibly be their ultimate goal behind these time warps, realities, timelines, AU , he didn't want to know who they were fully or even think about them he just wanted to find some place to rest and live peacefully but that wasn't the time to do so and would follow what Gaster said, on being a nomadic traveler until he could find some place to call home. As ATL sans continued to navigate through the complex array of timelines and realities, he caught a glimpse of an alternate universe where a familiar battle was taking place. It was a battle between a Chara and a version of sans that bore a striking resemblance to him. He watched with a mix of curiosity and unease as the battle unfolded. However, his heart sank when he saw the evil Chara slash their red knife across the chest of the alternate sans, leaving a wound that looked eerily similar to the one he had received in his own timeline.

The sight of the injury brought back painful memories and emotions that ATL sans had been trying to suppress. He took a step back from the window, his hand subconsciously gripping Chara's locket around his neck. It was a stark reminder of the pain and challenges he had faced, and the realization that these alternate versions of himself were facing similar struggles only amplified his feelings of melancholy.

Continuing on his journey, ATL sans came across a window that displayed a universe that felt oddly familiar. It was the original world of Undertale, a place where frisk looked young and innocent, and the monsters were living peacefully on the surface. Seeing the happiness and contentment of the characters he recognized from his own experiences, sans couldn't help but feel a pang of sadness. He knew that his own reality was far from the idyllic scene he was witnessing, and the stark contrast between the two worlds weighed heavily on his mind. With a bittersweet smile, ATL sans muttered to himself, "Heh, just wishful thinking, right? You ol' pile of bones." Despite the hardships he had faced and the uncertainties he was currently dealing with, he couldn't help but hold on to a glimmer of hope as he continued his exploration through the vast worlds and possibilities.

As ATL sans moved through the complex expanse of timelines and realities, he caught a glimpse of yet another alternate version of himself approaching from a distance. This time, the sans he saw was wielding a giant paintbrush, accompanied by another sans. He watched as they walked and then suddenly teleported away, leaving him intrigued but also slightly perplexed by their actions. Continuing his journey, ATL sans continued to peer through the windows of different worlds. Among the countless possibilities, he came across a reality that was noticeably darker and edgier than most. In this world, he saw a version of sans with a gold tooth and red eyes, exuding an aura of toughness. Standing beside him was a papyrus with sharp teeth and a spiked battle body, creating an overall sense of intimidation. It was a reality that contrasted sharply with the undertale world he knew so well. Curious about the nature of this universe, ATL sans observed the underfell world for a moment. He couldn't help but be fascinated by the stark differences in character personalities and appearances, wondering about the events and circumstances that had led to such an alternate outcome. Yet, even as he observed these divergent realities, he couldn't shake the feeling that his own reality held a unique significance, even if it was destined to fade away.

As ATL sans continued to explore the diverse array of alternate realities, he found himself constantly stealing glances at the undertale world that felt so familiar, yet so distant. There, he witnessed a scene that was a stark contrast to the reality he came from—a surface where humans and monsters coexisted peacefully, devoid of the struggles he had known he hesitantly approached the window and breathed heavily until he finally took the decision to enter. He was teleported to this world, a world where he wished he was in with his own broken timeline he thought and while walking and seeing some friendly monsters and humans greeting him from afar he felt like he was home but shook his head and knew this world wasn't his own and shouldn't interfere with other's lifes and eventually he  found a rag that he used as a cloak. Hidden in a cloak and watching from a distance, he observed the original sans going about his day seemingly content in a barbecue with his friends and family, yet with a hint of uncertainty lingering beneath the surface.