So later in the novel, Weed and Dain end up reuniting during one of Weed's quests and they both pretend that they don't know each other. I could never understand why Weed, who even claimed that she was his first love, would feign ignorance and Dain not even reveal that she's the same Dain and that she survived her operation. Can someone explain this to me?
As he told Yellowy, Weed assumed she disguised herself because she was trying to move on with her life, instead of her cowardly side making her incapable of telling him how she actually felt (which is keeping with how he saw her acting when she disappeared to go have surgery, and he didn't really see much of her inaction and fear before they met). So he decided to be Cruel to Be Kind to help her move on. Also his interest in Seoyoon had advanced quite a lot by the point Dain came back, so his current feelings weren't just going to change without a push.
Secret Sculpting Skills
It's always kind of bothered me that despite the fact that Weed has shown numerous times that the sculptor class has immensely useful and downright broken skills, no other sculptors have tried seeking him out to learn about the secret techniques. Can't any normal sculptor learn those skills like Sculptor Life Bestowal or Sculpture Transformation? Or do they have to possess the Moonlight Sculptor profession?
They can, at least in theory, also learn those skills if they learned them. The main problem is that those rare skills like Sculpture Transformation must be learned through specific quest and since Weed completed one where the sculptor died at the end one must go wait untill a new npc sculptor with the skill appears, which takes long periods of time.
Other sculptors are thousands upon thousands of sculptures behind Weed. They don't have the required intermediate or advanced sculpting yet. They haven't spent weeks in a single dungeon to uncover a unique skil. They haven't fought through forbidden zones with 400+ level monsters. Also keep in mind Weed's skill and grinding have raised his fighting ability way beyond a normal sculptor. So others will eventually get there, but Weed is moving at an insanely accelerated rate. Though if it makes you feel better, we do find out the leading architect in the game has a mass destruction level skill like Weed in the later volumes.