If we think about Snape, he would be a complex character in this crossover. He might initially think the survivors of The Walking Dead are unworthy of his help. But as he sees their determination, he could change his mind. The characters from The Walking Dead would be in awe of the magic potions and spells. The Mashone could be a group that has a deep understanding of both magic and survival. They could help the Potter characters understand the harsh reality of the zombie - infested world and also help the Walking Dead characters appreciate the power of magic.
Hermione would probably be very interested in studying the situation in The Walking Dead world. She might try to find a scientific or magical explanation for the zombies. The survivors from The Walking Dead, like Rick, would be initially skeptical of the magic but would soon see its value. The Mashone could act as mediators, helping both sides understand each other. For instance, they could explain the ways of the Potter world to the survivors and vice versa.
In a fanfiction, Harry Potter himself could use his skills in Defense Against the Dark Arts to fight the zombies. He would be amazed at the survival skills of the characters from The Walking Dead. Daryl, for example, could teach Harry some of his hunting and tracking skills. The Mashone could bring in their own cultural elements. Maybe they have a special way of communicating that helps in coordinating between the two groups. They could also have unique magical abilities that are different from what's seen in the Potter world and use them to everyone's advantage.
Chapter 618, "Abandoned Again", is the clearest early answer because it turns Sister Xiao Wan's situation into a concrete plot event. It opens with Upon hearing this, Jiang Cheng looked at Su Yinwan in disbelief.
Chapter 767, "Jiang, Jiang Yu?!", is the clearest early answer because it turns Jiang's situation into a concrete plot event.
Chapter 384, "To celebrate my selection, live streaming tomorrow night.", is the clearest early answer because it turns Don's situation into a concrete plot event. The chapter gives readers a real answer by opening on How much funding are you expecting?" After reviewing the documents,...
Chapter 433, "The Young Master Has His Own Ideas", is the clearest early answer because it turns Jiang Li's situation into a concrete plot event.
Chapter 443, "Did Jiang Li Steal Team F's Home?", is the clearest early answer because it turns Wenwen's situation into a concrete plot event.
Chapter 379, "Is This the Way Huaxiu Treats Its Guests?", is the clearest early answer because it turns Huaxiu's situation into a concrete plot event. The chapter turns that into something concrete by moving from Song Man chuckled twice, evidently displeased, and then positioned...
Chapter 712, "This is definitely not reliable!", is the clearest early answer because it turns Jiang Tienshen's situation into a concrete plot event. The chapter gives readers a real answer by opening on Exactly, exactly." Wen Jiaojiao said discontentedly, her arms crossed.
Chapter 606, "Are There Crocodiles?!", is the clearest early answer because it turns Shang Shaojing's situation into a concrete plot event. It opens with Hearing Ji Yanbai volunteer to stay behind, everyone ceased to have...
Chapter 393, "Clearly Marked Prices, No Deception to Young or Old", is the clearest early answer because it turns Shang Shaobai's situation into a concrete plot event.
Chapter 642, "Congratulations to Qi Tianyu, Points Increased by 10!", is the clearest early answer because it turns Congratulations's situation into a concrete plot event. A useful checkpoint is the way the scene starts with We'll be the first to catch the plane, then we head straight to party!