Well, first, you need to think about the setting. Since Percy Jackson is in a world with Greek gods and the Avengers are in a more modern, sci - fi world. You could bring Percy into the Avengers' world through some kind of magic portal. Then, for the plot, Percy's knowledge of ancient magic and mythology could help the Avengers deal with a threat that has roots in ancient times. His sword, Riptide, could be a unique weapon against an enemy that the Avengers' usual weapons can't handle.
One way could be to have Percy Jackson's powers of being a demigod interact with the superpowers of the Avengers. For example, his ability to control water could be used in a joint mission with Thor's lightning powers. Maybe they are facing a common enemy that can only be defeated by combining their unique skills.
Chapter 236, "White Dew Gu, Despairing Yuwen Dao, Yang Lu", is the clearest early answer because it turns Han Jiuli's situation into a concrete plot event. It opens with After all, Yang Lu is a giant camp, with a population of just over... and closes on Their sense of suffocation and fear grew simultaneously, no wonder....
Chapter 295, "Deploying the Beehive, Splitting into Two Forces (2)", is the clearest early answer because it turns Xia Hong's situation into a concrete plot event. It opens with How is the situation in Mirror Valley now?" "After nightfall, seven... and closes on A Long Mountain so large, it's impossible for the Li Family to....
Chapter 190, "Xia Li, 4 Articles, Someone is Coming", is the clearest early answer because it turns Xia Li's situation into a concrete plot event. The setup is Upon hearing this question, a peculiar expression appeared on Xia..., but the pressure keeps building through Someone actually asked, my brother really is foresighted!.
Chapter 220, "Difficult Journey, Yucheng's Ordeal, Li Xuanling 2", is the clearest early answer because it pushes Ma Yong into a new phase or setting. A useful checkpoint is the way the scene starts with Xia Hong's eyes flickered slightly, calculating in his heart while... and follows through with But as Peng Bo said, who would target him this deep into Long....
Chapter 276, "Integration of Soldiers and Hunters, Military System, and Roll Call Hunt", is the clearest early answer because it turns Cold Resistance Level's situation into a concrete plot event. A useful checkpoint is the way the scene starts with Second Year of Great Xia, June 4th. and follows through with Breaking through to the thirty thousand jin limit allows army....
Chapter 297, "Hou Jing's Unusual Behavior, Hou Kong's Decision", is the clearest early answer because it turns Hou Kong's situation into a concrete plot event. The setup is In the forty-eighth year of Longyou, June 22, after midnight On the..., but the pressure keeps building through The front of the queue is filled with young and strong men, the.... Once the chapter lands on White Abyss had already merged into Zhaoyang in April;
Chapter 240, "An Offer You Can't Refuse, Narrow Escape (Part 2)", is the clearest early answer because the buildup finally cashes out in a real clash. The chapter turns that into something concrete by moving from Qiu Peng paused here, held up three fingers, and continued: "Firstly,... to How would they feel after hearing it?" The three conditions were:....
Chapter 231, "Investigating Yang Lu by Day—Whose Side Are We On?", is the clearest early answer because it turns Wu Tianxing's situation into a concrete plot event. Early on, They are now located southeast of the hill, and the west side happens.... By the end, Two on the first floor, four on the second floor, one on the third....
Chapter 245, "Cause and Effect, the Bigger Picture, Return to the Beehive (Part 2)", is the clearest early answer because it pushes Xia Chuan into a new phase or setting. Early on, Everyone's face changed dramatically when they saw Xia Hong's wound.. By the end, When Meng Yi returned to Xia City with the message this morning, he....
Chapter 214, "Meritorious Deed, A Fortunate Accident (Part 3)", is the clearest early answer because it turns Xia Hong's situation into a concrete plot event. The chapter gives readers a real answer by opening on Among the hunting team's thirty-odd squads, the one with the... and ending on The head doesn't go hunting often..