I’m betting he won’t be able to give the orb to Taehyuk. We see in chapter 47 he is still practicing to focus his power and form the orb. He’s still not able to finish it’s creation. I think Hyo-un will be heavily drained due to his constant practice to form the orb and Taehyuk will die before Hyo-un can give it to him. He’ll just be too weak.
As for his loss of memory. I think that’s due to his prolonged sleep and possibly the emotional trauma that caused his slumber. The mind can block out traumatic memories to protect itself. At the end of season 1 it seemed Hyo-un’s sickness may have been his mind or dragon spirit attempting to “fix” him.
Just guessing of course but the hints give me this impression.
finally, the good part. the angst i've been waiting for. i wouldn't be surprise if the flashback is gonna be the whole arc for season 2. it doesn't seems like it's gonna end for at least 3-5 more chapter.
i don't mind this flashback but i wasn't too keen on their relationship here bcs well the taehyuk in the past multiple times said no. i'm afraid hyo-un is gonna put the orb on taehyuk in order to save him (if he died, and it will not work ofc taehyuk will still be dead) but i do hope it's taehyuk himself that like consented or wants the orb. bcs if it was "by force" meaning the present taehyuk is basically enchanted to be his mate and his feelings might not be from him 100%. the better ending is taehyuk died without eating the orb bcs hyo-un also feels guilty about giving it to him? for fabricating taehyuk's love for him? so that all of the affection taehyuk has for hyo-un in present time all comes from himself. that's why hyo-un also can't remember what taehyuk face look like. he has zero connection to the past. this is all just a theory ofc