If Naruto were an X - Men, his Nine - Tails chakra could be a super - power on its own. Maybe it could be like the Phoenix Force in terms of being a very powerful and sometimes uncontrollable source of energy. Sasuke's Rinnegan could give him a whole set of powers similar to multiple X - Men combined. For example, the ability to absorb and manipulate energy like Rogue or the teleportation - like powers of Nightcrawler.
In the X-Men movie, the White Queen was a powerful female wizard who once fought against the evil Professor X to protect humans. In the movie, the White Queen finally succeeded in eliminating the evil Professor X and protecting mankind from the invasion of evil forces. However, she also paid the price of losing her husband and child. Although the White Empress 'ending was happy, it was also full of sadness.
Naruto's Rasengan could be used in a similar way as some of the physical attacks in One Piece. For example, it could be as powerful as Luffy's Gear attacks. Also, his ability to jump great heights and distances might be on par with some of the Zoan Devil Fruit users' enhanced physical abilities.
Rimuru Tempest has a wide range of powers. One of his main abilities is the power of Gluttony. This allows him to devour almost anything and gain knowledge or abilities from it. For example, he can devour monsters and acquire their skills, which makes him extremely versatile in combat.
If the X - Men were in the Frozen universe, they would bring a new dynamic. Wolverine's healing factor would make him a valuable asset in the cold and dangerous environment. He could withstand extreme cold and any injuries that might come from the ice. Storm could collaborate with Elsa to create more elaborate weather patterns. The X - Men's mutant status could also cause some interesting reactions among the people of Arendelle, who are not used to such extraordinary abilities. It could lead to a story about acceptance and cooperation between two very different groups.
Loki, the God of Stories, has the power of shape-shifting and can assume various forms. He's also highly intelligent and skilled at deception and manipulation.