I think Bulbasaur would be a good match. Naruto has a strong connection to nature in his own world, and Bulbasaur is a nature - based Pokemon. Naruto could use his knowledge of plants from his ninja training to help Bulbasaur grow stronger.
Yes, there is. The world of fanfiction often combines different popular franchises. Naruto and Pokemon are both highly popular, so it's not uncommon for fans to create stories where the two universes intersect. These fanfictions can range from simple crossovers where Naruto characters encounter Pokemon, to more complex stories that blend the elements of both worlds like ninja using Pokemon in battle or having Pokemon in the Hidden Leaf Village.
Definitely Pikachu. Since Naruto is often in need of a quick and agile ally, Pikachu's speed and electric attacks would be very useful. Plus, Pikachu's cute appearance but powerful abilities would create an interesting contrast with Naruto's ninja style.
Naruto would probably choose a Pikachu first. Pikachu is energetic and has a lot of spunk, just like Naruto. They would both be full of enthusiasm and would make a great team right from the start.
Naruto would probably be really curious about Pokemon. He might try to use his ninja skills to catch them in a really acrobatic way. And with the Nine - Tails' power, he could potentially sense the strength of different Pokemon. He'd likely befriend the more friendly - looking ones first and might even try to ride on some of the bigger Pokemon like a Charizard or a Gyarados if he could manage it.
His Rinnegan might allow Naruto to have a psychic connection with Pokemon. He could use this to soothe wild Pokemon or even tame them without using pokeballs in some cases. When it comes to battles, his ability to use multiple jutsus could be translated into strategic moves with his Pokemon. For example, he could combine a water - type Pokemon's move with his own wind - style jutsu to create a more powerful attack.
From Naruto, obviously Naruto himself would be a main character. Sasuke could also be there, maybe he's initially skeptical about the Pokemon but then warms up to them. In the Pokemon world, Ash and Pikachu are must - haves. Misty and Brock could also show up to offer their expertise in Pokemon training.
I think Mewtwo would be the most fascinating for Naruto to talk to. Mewtwo is a very intelligent and powerful Pokemon. It has complex thoughts about its existence and purpose. Naruto, with his own struggles and growth in the ninja world, could have deep philosophical discussions with Mewtwo. They could exchange ideas about power, identity, and what it means to be different in their respective worlds.
A common trope is the idea of the Pokemon having chakra. This allows for some interesting interactions between the Naruto and Pokemon universes. Also, there's the trope of Pokemon trainers from the Pokemon world ending up in the Naruto world and having to adapt to its ways. They might end up in a ninja village and have to learn about ninjas and their skills. Sometimes, there are crossovers where legendary Pokemon play a big role in Naruto - related events, like helping to defeat a powerful enemy in the Naruto world.
Naruto himself would be a great addition. His determination and ability to never give up would translate well into being a Pokemon trainer. He could bond quickly with his Pokemon. Also, Kakashi would be good. His intelligence and strategic thinking would help in planning battles. And then there's Shikamaru. His lazy - but - brilliant mind could come up with unique battle strategies using the Pokemon's abilities.