Last night was such a good session of Persona 5 that when I was asleep, my dream got my wires crossed between xenoblade and Persona 5 I think...! Including Mythra showing up with Pyra's sword, saying "Rex has to be stopped..." and a mysterious guy who would join you to fight alongside you sometimes, but also he didn't really like you and was kind of a rival. He was basically a wizard. I don't remember what kind of weapon he had but he used it like a mage would use a book.