A possible plot is that there's a crossover of the two worlds' forms of transportation. The Hogwarts Express could somehow end up in the FMA world, or perhaps Edward discovers a way to create a magical - alchemical portal between the two worlds. This leads to an exchange of students and wizards. Some of the Hogwarts students are fascinated by alchemy and want to learn it, while Edward and Alphonse are eager to learn more about magic. However, there are also some who oppose this exchange, fearing it will bring chaos, and they try to stop it, creating a conflict that the main characters have to resolve.
Well, a cool plot could be that the Death Eaters are interested in the power of alchemy. They try to capture Edward to force him to use alchemy for their evil purposes. Harry, Ron, and Hermione then rescue him. In return, Edward offers to help them with his alchemical skills in their fight against Voldemort. For example, he could use alchemy to create unique magical items or barriers. Also, Alphonse could befriend some of the Hogwarts ghosts and learn about the secrets of the castle from them, which could be useful in the fight against the dark side.
Chapter 235, "The Might of the Longyou Army, Yang Lu's Desperate Plight", is the clearest early answer because it turns Wu Ying's situation into a concrete plot event. It opens with On the night of April 14, Xia Hong indeed personally witnessed the... and closes on First take some interest for He Tu, die!" Li Xuantiang's voice was....
Chapter 152, "Mirror Immortal's Killing Intent, Who Has Fallen?", is the clearest early answer because the violence around Leader Xia Hong becomes final instead of hypothetical. The setup is At the same time, behind Yuwen Hu, two to three hundred people..., but the pressure keeps building through Truly, the wheel of fortune turns!.
Chapter 157, "The Disappearance of the Cold Beast, Breakthrough Tide", is the clearest early answer because Xia Hong finally turns buildup into a real advancement. The setup is Within five hundred meters of the perimeter, all low-level Cold..., but the pressure keeps building through After a brief moment of thought, Shi Ping also agreed with the two's....
Chapter 188, "Venting, Drawing Lines, Preparations", is the clearest early answer because it turns Hive Camp's situation into a concrete plot event. It opens with Xia Hong in the front heard the sound, immediately turned to look at... and closes on I've confirmed with the other teams, none of them went deeper than.... The key payoff is that the chapter closes with "Alright, then I'll take everyone back now.
Chapter 196, "Sword Puppet, the First Intermediate Squad", is the clearest early answer because it turns Thunder Kui's situation into a concrete plot event. It opens with Qiu Peng knew this very well, so the target of his broad knife could... and closes on From within the piled snow, a crimson giant lying flat suddenly sat....
Chapter 164, "The World in the Mirror, Immortal", is the clearest early answer because it turns Yuwen Hu's situation into a concrete plot event. The setup is That Xia Hong's strength is actually so formidable, it's actually so..., but the pressure keeps building through His two silvery pupils, like two mirrors, slowly revealed a person....
Chapter 149, "Supreme Combat Body, The Dangerous Gao Yu【Please Vote】", is the clearest early answer because it turns Deceitful Monster's situation into a concrete plot event. The chapter turns that into something concrete by moving from Considering Great Xia's current activity area, a Cold Resistance... to This person's fleeing was still being hunted by an Intermediate....
Chapter 217, "Hesitation, Departure, and Sending Word (Part 2)", is the clearest early answer because it pushes Luo Cheng into a new phase or setting. A useful checkpoint is the way the scene starts with Wu Tianxing's words once again plunged Chen Yingyuan into a quandary. and follows through with Leaving my father and others here, I won't be at ease..
Chapter 201, "Five-Origin Garrison, Cold Marrow Iron", is the clearest early answer because the buildup finally cashes out in a real clash. The setup is At this moment, it was the latter half of the night, and outside the..., but the pressure keeps building through Yet inside the wooden cabin, warm currents surged like tides, as.... Once the chapter lands on Since that was the case, it was normal for them to have better..., the chapter closes with The doors were wide open at that moment.