I am prone to over-complicating things and ranting so I'm gonna give a rough short outline. basically, it's a little bit like a sequel (kinda) where Frisk falls into a coma shortly after a pacifist run, in the coma, they dream about their journey but have lost all memories of it. It's a fever dream. all of Frisk thoughts affect this dream and their subconscious still remembers a little bit so the character's actions are very similar, but because Frisk's thoughts affect the world, they end up hurting their friends the same way how sometimes in dreams when you hope something doesn't happen and it happens because of your very thought. they fix it because (via thoughts of course- this explanation is kinda repetitive) immediately and it looks a little thing like a glitch still lingers though where for a split second they looked crippled again before going back to normal. When Frisk reaches the end of their journey, they wake up and begin experiencing a severe form of delirium where all the sins they committed in their dreams still linger in the real world and torture them, they could be talking to Sans and they'll see the sans from their dream instead, with a large 'X' over his face and his eyes hollow saying things like 'it's your fault' 'you deserve this' 'i was just trying to be your friend' and 'why'. from sans' perspective in this situation, it will just look like Frisk crying and shaking his head yelling 'It's not my fault' 'I'm sorry!' 'It's his fault' 'Please!'. (did I mention the whole dream and coma was an experiment by this au's gaster? (aka why they yelled 'it's HIS fault' )) So yeah, It's very dark. :)
