Responses
it wasn't "needed", they were given a choice, the choice was a gift from the red thread, it's their choice if they want to forget or not. yeon wanted kihoon to forget him. because he feels guilty, he wanted to see a version of kihoon unbounded by the past and the red thread.
also about kihoon misfortune!! in season one, it was purged using the red thread quests, by completing the quests all kihoon's misfortune disappeared.
Hey so like I’m supper confused, I don’t understand why they needed to erase his memories? So he won’t be cursed anymore because of when he was a kid he tied the red string to him? ┗( T﹏T )┛