Another plot could involve a shared enemy that is a combination of a Grimm and a Persona - like entity. The RWBY and Persona characters would have to combine their skills and knowledge. The Persona characters could introduce the concept of Social Links to the RWBY world, and through building relationships, they all gain new powers to fight this strange new foe.
One idea could be that the RWBY characters enter the Metaverse from Persona. They might have to face their Shadows, which could be related to their Grimm - fighting fears or personal insecurities. For example, Ruby could face a Shadow that represents her fear of not being able to protect everyone.
Maybe the Persona characters end up in Remnant. They could help the RWBY teams with their unique Persona abilities. The Velvet Room could also exist in Remnant in some form, and Ozpin might have a connection to it. The Persona users could teach the RWBY characters about the power of the mind and how to use it in combat.
A practical answer is Chapter 122, because it turns the idea into a concrete scene. The chapter opens with Damn, are we supposed to find the points card in the mud?!" He had just..., adds pressure through It wasn't intentional!" Bullet screen: "[Qi Tianyu, you really need to be..., and ends on He.
If you want the clearest chapter reference, go to Chapter 125. Early on, Next, it was Qi Tianyu's turn.; later, the chapter leans on Although he didn't know what Jiang Li had chosen, just from her recent....
Chapter 79 is the strongest chapter-level answer because it starts from Jiang Li leisurely said, "I bought this weeding machine, and according to... and follows through on Um..." Wen Jiaojiao bit her lip, "Could you, could you lend me the weeding....
The best chapter pointer here is Chapter 100, "Ominous, there might be a bloody disaster!". It opens with The barrage was about to die of laughter. and closes on Her eyes flickered slightly as she grabbed the hand..
If you want the clearest chapter reference, go to Chapter 115. Early on, Jiang Yan was woken by a loud crowing noise.; later, the chapter leans on Annoyed, he opened his eyes and saw that the hen, which should have been....
Chapter 147 is the strongest chapter-level answer because it starts from Xiao Xueyi nodded in agreement after listening. and follows through on Only Jiang Li glanced back at Director Sun, and then took out her own....
Chapter 126 is the strongest chapter-level answer because it starts from Wen Jiaojiao initially wanted to cause trouble. and follows through on The trolls lurking in the live stream immediately seized the opportunity....
A practical answer is Chapter 100, because it turns the idea into a concrete scene. The chapter opens with The barrage was about to die of laughter., adds pressure through Who would dare write a script like this!], and ends on Her eyes flickered slightly as she grabbed the hand..
The best chapter pointer here is Chapter 112, "The Strange "Team Spirit" Appears". It opens with These five people are supposed to be at odds. and closes on [Hahahaha why is the Princess starting to look disappointed?] [Help, even....
Chapter 131 is the strongest chapter-level answer because it starts from Just around mealtime, Director Sun came over pushing his small food cart. and follows through on Hungry, they no longer cared about their appearance, quickly washed their....