SkyTale: Wings in the sky

Sans, papyrus and the rest of the underground is freed from their underground prison. It been a couple of months, but it's happy. Frisk promised not to reset, a real promise. Chara made sure the promise was kept. many humans excepted them, but many also didn't. But honestly, they didn't care. Then one day, Papyrus decided to go in vacation at a mountain along with the others. Another mountain that was near mount ebott. Sans originally didn't want to go, but papyrus made him go with him telling the older skeleton 'That fresh air is needed, and exercising is healthy and good'. But what they didn't know was that an adventure is coming, A new pal joined the adventure, A pal from the mountain. A mountain that has a legend of its own.
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This is a timeline I thought off. I hope you enjoy it and please don't steal it as your own. I also am not sure if this is an AU or a timeline lol