Well, a really interesting plot twist could be related to the prophecy. If Harry is Regulus' son, it could change the interpretation of the prophecy completely. Instead of being the 'Chosen One' in the way we thought in the original series, it could be that his role as Regulus' son gives him a different mission. Maybe it has something to do with redeeming the Black family name and using the knowledge Regulus had about the Dark Lord to defeat him in a more unexpected way. This could also lead to a different relationship with Dumbledore, as Dumbledore might have known about Harry's true parentage all along and been guiding him differently.
One possible plot twist could be that Harry has hidden magical abilities passed down from Regulus that no one expected. Maybe he can communicate with certain magical creatures in a unique way.
A plot twist could be that the truth about his parentage changes his relationship with the Malfoy family. Since Regulus had some connection to the Dark Arts initially, it might make the Malfoys see Harry in a different light, perhaps as a potential ally in a different way than in the original story.
Chapter 348, "Zhu Ling in Dire Straits, Eight Camps Martial Contest, Betting Five Years—East Ridge Has Fallen!", is the clearest early answer because it turns East Ridge's situation into a concrete plot event. It opens with When the Cold Resistance Level observes the Earth-digging Realm, it... and closes on The top three camps have their tribute materials shared by the....
Chapter 350, "Methods to Enhance the Peak of Cold Resistance, Moao's 10th Town, Beishuo Yang Fa, Nightmare, East Ridge Lu Yun", is the clearest early answer because it turns Zhu Ling's situation into a concrete plot event. The chapter turns that into something concrete by moving from Lu Yang, Zhao Hu, what a bold East Ridge, daring to act so recklessly... to I found your physique curious and have a few questions for you."....
Chapter 55, "I Can Prove Everything Miss Jiang Said Is True!", is the clearest early answer because it turns Li Garden Hotel's situation into a concrete plot event. It opens with Su Yinwan hadn't expected that, in just one day, Jiang Li's...
Chapter 34, "Official Recording!", is the clearest early answer because it turns Shang Shaojing's situation into a concrete plot event. Early on, Seeing that the public sentiment wasn't quite right, Su Yinwan felt....
Chapter 69, "Received Two Advertisements on the First Day", is the clearest early answer because it turns Director Sun's situation into a concrete plot event. The chapter turns that into something concrete by moving from Since the phones issued by the program team couldn't log into Weibo,...
Chapter 59, "Kicked Out", is the clearest early answer because it turns Jiang Yan's situation into a concrete plot event.
Chapter 74, "Ordinary People", is the clearest early answer because it turns Kang Bazi's situation into a concrete plot event. Early on, Having seen Jiang Li's ID before, he knew that this person named.... By the end, The man's phoenix eyes narrowed slightly, he looked at the girl....
Chapter 253, "She Hit My Head Three Times, I Hit Hers Seven Times", is the clearest early answer because it turns Times Wen Jiaojiao's situation into a concrete plot event.
Chapter 181, "Are All the Weibo Followers Police?", is the clearest early answer because it turns West District Police's situation into a concrete plot event. Early on, Xiang Hao rushed to the police station as soon as he saw the trending....
Chapter 249, "Maxing Out Wilderness Survival Skills!", is the clearest early answer because the violence around Jiang Yan becomes final instead of hypothetical. The chapter turns that into something concrete by moving from Jiang Yan's body subconsciously shivered twice.