DC was founded before Marvel. DC has been around since the 1930s, laying the foundation for the superhero comic genre. Marvel followed suit a little later but has also made significant contributions.
Because Doraemon was not a character in the Marvel Universe. Doraemon was a Japanese manga and anime character that appeared in the Doraemon series. Although Doraemon was a fictional character, it had shown some powerful abilities in the anime, such as time travel and teleportation doors, so it was loved by some fans.
The time in the Marvel Comics universe is not straightforward. It can be fast-paced or slow, depending on the narrative needs and creative directions of the writers and artists.
I think it could be Captain America. Cap is always looking for good - hearted individuals to fight alongside. Naruto's determination and loyalty would appeal to him. Also, Naruto could learn a lot from Cap's leadership skills.
Well, Naruto's unique ninja skills like shadow clones and rasengan would be quite a shock in the Marvel Universe. He could probably team up with Spider - Man. Naruto's agility and combat skills combined with Spider - Man's web - slinging and spider - sense would make them a formidable duo against villains.