One idea could be exploring Overhaul's backstory in more depth. Maybe show his childhood and what led him to become the villain he is. Another could be a redemption arc for him, where he teams up with the heroes against a greater evil.
You could write a fanfiction where Overhaul's quirk is used in a different way. For example, instead of using it for destruction and crime, he uses it to heal people in a post - apocalyptic world where medical resources are scarce. This would completely change his character dynamics and relationships with other characters in the 'Boku no Hero Academia' universe.
A really interesting concept could be a time - travel fanfiction involving Overhaul. He could go back in time and try to prevent certain events that led to his downfall. Along the way, he might have to interact with younger versions of the heroes and villains, which could lead to some very unique and unexpected storylines.
Chapter 282, "Humiliation and the Formation of the New Army (Part 3)", is the clearest early answer because it turns Yang Zhong's situation into a concrete plot event. The chapter gives readers a real answer by opening on The structure of the Longyou Army is one Capital Commandant and four... and ending on His tone became unusually calm as he continued: "If we go to Great....
Chapter 207, "Improving Corvée Labor and Changes in the First Year", is the clearest early answer because it turns Hunting Department's situation into a concrete plot event. The chapter gives readers a real answer by opening on Inside the main hall, more than a hundred people, and tens of... and ending on This is equivalent to seven times the original Mirror Immortal Camp..
Chapter 288, "On the March, Hou Hu's Wrath", is the clearest early answer because it turns Cloud Dragon Army's situation into a concrete plot event. The chapter turns that into something concrete by moving from A bit faster, it's been half an hour and we've only covered a... to He froze momentarily, looking up at Xia Chuan with a puzzled....
Chapter 306, "Rebel Collaborators, Chaos and Opportunism, Long Mountain Changes Hands", is the clearest early answer because it turns Great Xia's situation into a concrete plot event. The chapter gives readers a real answer by opening on Go notify the leader, have him quickly bring the main forces back to... and ending on His initial thought was that the trials Li Hu suffered would instead....
Chapter 326, "Divide and Annihilate, Shattering Divine Light, Trump Card Activated!", is the clearest early answer because it turns Frost Wolf's situation into a concrete plot event. The setup is A Frost Wolf less than two meters in length suddenly charged out from..., but the pressure keeps building through It fixated on the Cold Ruins Tripod burning atop the Snow Hill, and....
Chapter 229, "The Dust Settles, Beehive in Hand (Part 3)", is the clearest early answer because it turns Hou Bing's situation into a concrete plot event. A useful checkpoint is the way the scene starts with Wu Tianxing lay on the ground, his face full of horror. and follows through with Beehive is ruined!" A trace of sorrow flashed in Chen Yingba's heart,....
Chapter 292, "White Dew Gu's Open Plot, Long Mountain Advances", is the clearest early answer because Li Tiancheng finally turns buildup into a real advancement. The setup is Over an hour ago, Li Tiancheng described to them everything he had..., but the pressure keeps building through A total of ten kilometers of black stone walls on three sides; Xia....
Chapter 264, "Supplies Delivered, News from Long Mountain", is the clearest early answer because it turns Wu Tianxing's situation into a concrete plot event. It opens with Second Year of Great Xia, May 20 Wushuang Giant Stone Camp, Top Floor... and closes on Wushuang and Hanqiong still have defense duties, so Xia Chuan took.... The key payoff is that the chapter exposes hidden motives around Wu Tianxing, so readers can finally see how the conspiracy layer of the plot is actually moving.
Chapter 260, "Medicine Workshop Upgrade, Population Surge, and Resource Easing", is the clearest early answer because the rescue effort creates visible on-page results. Early on, From April 29 to May 9, the massive population migration finally.... By the end, From the perspectives of Cold Beasts, vegetation, herbs, and....
Chapter 232, "Saving Lives, Putting on an Act, Xia City in Uproar [8,000-Word Chapter, More to Come]", is the clearest early answer because the rescue effort creates visible on-page results. The chapter turns that into something concrete by moving from Five against two, a fierce battle reignited. to Whether through fire or sword, Peng Bo will never refuse!" Yuan Cheng....