Sakura could also adapt well. She's intelligent and has shown great determination in Naruto. In the Persona 3 world, her medical knowledge could be useful, and she could use her smarts to figure out how the Persona system works. Plus, her growth from a shy girl to a strong kunoichi would translate well into the challenges of the Persona 3 universe.
I think Naruto would be a likely candidate. He's always been adaptable and open - minded. His experience with the Nine - Tails and his own growth as a ninja would help him in the Persona 3 world. He would probably be eager to make new friends and form Social Links, and his positive attitude could be a great asset when facing the Shadows.
Ryan could also adapt well. He's always trying to be something he's not in the office. In the Twilight world, he could embrace the opportunity to be a cool vampire or a powerful werewolf. He might use his charm (or what he thinks is charm) to navigate the Twilight society.
Ruby could also be a great candidate. Her natural leadership skills and her ability to quickly adapt to new situations would serve her well. Plus, her speed and agility could make her an excellent Pilot. She might even come up with new strategies for using the Titans in combat, inspired by her own experiences in RWBY.
Akira and Minato would be an interesting pairing. Akira, with his leadership skills as the leader of the Phantom Thieves, and Minato, the protagonist of Persona 3, could share their strategies in combat and dealing with the Metaverse. They both have different experiences with their respective groups, so they could learn a lot from each other.
The interaction between Yu Narukami from Persona 4 and Makoto Yuki from Persona 3 could be really interesting. Yu is a very calm and perceptive leader, while Makoto has his own sense of leadership. They could share their experiences in leading their respective teams and learn from each other.
Well, first of all, Jiraiya might return in some form, like a spirit guide or something, and be an ally to Naruto. Tsunade would also be there, using her leadership and medical ninjutsu. And then there are the new generation characters like Boruto. He could learn from Naruto and help out, seeing as he also has his own unique abilities. The Allied Shinobi Forces from the previous big battles might also reunite to support Naruto in saving the world.
Naruto would first have to adapt to the different magic system. Since he's used to chakra, understanding the arcane, fel, and nature magic in Warcraft would be a challenge. But he's a quick learner. He might start by observing the mages in the world. Also, he'd need to adapt to the new races. He'd probably be curious about the elves, dwarves, and orcs, and try to make friends with them using his friendly and outgoing nature.
I think Naruto would be a likely candidate. He has always been eager to learn new powers and has a great capacity for growth. His determination and strong will would serve him well in the process of becoming a Zanpakuto master. He would face the challenges head - on and use his unique skills, like his shadow clones, to practice and master the Zanpakuto techniques.
It's hard to say. Naruto has his powerful Nine - Tails Chakra and Sage Mode. But the five kages are also very strong. However, Naruto has a habit of coming out on top in tough situations, so he might be the likely winner.
It could be Orochimaru. He is always interested in new forms of power and Corrin's unique abilities would attract his attention. He might try to capture Corrin to study her dragon powers and use them for his own evil purposes. Naruto would then have to protect Corrin from Orochimaru's clutches.
Sakura would be a likely candidate. She's a medical ninja, and she has always cared about Naruto. She would use her medical skills to try and stabilize him.