Glass Love Was Never Betrayed

So what is the regret in "Love and Redemption"?

It is that Si Feng never knew that, although Xuanji lacked all six senses and could not tell beauty from ugliness, she was still dazzled by him the moment she lifted his mask; that, although Xuanji had no heart, she went two days and two nights without food or water and ultimately grew a heart lamp for him; that Xuanji was not as unmoved by his confession and kisses as he thought; that Xuanji had not broken and thrown away the hairpin he gave her; and that Si Feng always believed Xuanji treated him no differently from anyone else, when in truth he had long since become the one irreplaceable person in her heart.

So when they return to the past and relive everything that happened back then, what will they, now both observers and participants, feel about all those misunderstandings?

(This book focuses on Xuanji and Si Feng clearing up every misunderstanding. Most of it is presented in dialogue, so readers should imagine Si Feng and Xuanji speaking and behaving as they do in the show.)