So the side story is just the third timeline... They could've just turned it to season 4 but I understand why the manhwa version turned it into a side story and a 'what-if'. For the sake of every manhwa and novel reader's sanity, season 3 (second timeline) is the final of the main story and it ends in a happier note so I'm not complaining... But yet again third and the other alt timeline are angsty as heck┗( T﹏T )┛
So the side story is just the third timeline... They could've just turned it to season 4 but I understand why the manhwa version turned it into a side story and a 'what-if'. For the sake of every manhwa and novel reader's sanity, season 3 (second timeline) is the final of the main story and it ends in a happier note so I'm not complaining... But yet again third and the other alt timeline are angsty as heck┗( T﹏T )┛