One common theme could be discovery. Harry might discover the unique properties of moltencheese in the context of magic.
Another theme could be friendship. For example, Harry and his friends work together to deal with situations involving moltencheese, just like they do with other magical challenges in the original series. They support each other and use their combined skills and knowledge to overcome difficulties related to the moltencheese.
The theme of mystery is also likely. Since moltencheese isn't a part of the original Harry Potter lore, fanfiction writers would probably create a sense of mystery around it. It could be something that has been hidden in the wizarding world for ages, and Harry stumbles upon it during one of his adventures. There might be secrets and prophecies associated with it, making it an alluring element for the story.
Chapter 183, "Sacrifice Oneself, Break Them Up!", is the clearest early answer because it turns Jiang Yan's situation into a concrete plot event. The chapter turns that into something concrete by moving from Seeing that he held a blue ball identical to Su Yinwan's, Jiang Yan...
Chapter 201, "Passing the Door Three Times without Entering", is the clearest early answer because it pushes Miss Jiang into a new phase or setting. Early on, The third time she passed by happened to be when she was rushing back....
Chapter 286, "I Won't Let Anything Happen to Either of Us", is the clearest early answer because it turns Jiang Li's situation into a concrete plot event. The chapter gives readers a real answer by opening on Throughout these reincarnations, Zhao Lang had gradually discerned a...
Chapter 40, "The National Museum Speaks!", is the clearest early answer because it turns Wen Jiaojiao's situation into a concrete plot event. The chapter turns that into something concrete by moving from [Jiang Li claims she copied this herself?
Chapter 195, "Woke Up and the Base Was Stolen?!", is the clearest early answer because it turns Shu Yan's situation into a concrete plot event. It opens with Jiang Yan was fully equipped and followed at the end of the team.
Chapter 120, "Jiang Li Can Actually Do Acupuncture?!", is the clearest early answer because it turns Is's situation into a concrete plot event. The chapter gives readers a real answer by opening on Facing the sudden and somewhat strange request from Jiang Li,...
Chapter 429, "Is There Such a Good Thing?!", is the clearest early answer because it turns Guan Xiong's situation into a concrete plot event. The chapter turns that into something concrete by moving from [What's going on?]" "[What happened, why is Team G causing a...
Chapter 103, "Selling a Kidney to Repay Debt", is the clearest early answer because it turns Jiang Li's situation into a concrete plot event. It opens with Jiang Yan looked at Zhao Lang with suspicion, eyeing the dark... and closes on Jiang Yan felt deep guilt welling up inside him..
Chapter 164, "Congratulations to Jiang Yan for scoring one point!", is the clearest early answer because it turns Director Sun's situation into a concrete plot event. The chapter gives readers a real answer by opening on Damn, the production team is so shady, they're still doing a live...
Chapter 221, "No Choice, He Gave Way Too Much", is the clearest early answer because it turns Hua University's situation into a concrete plot event.