Naruto would gain some really cool (pun intended) new abilities. The ice - making ability would be the most prominent. He could form ice clones, similar to his shadow clones but with the added advantage of being made of ice and potentially having more durability. His sensory abilities might also be enhanced, as Esdeath has a good sense of her surroundings when using her powers. He could detect enemies hidden in the ice or snow. And, like I said before, the time - freezing power. This would allow him to analyze his opponents' moves during the frozen time and come up with the perfect counter - attack. It would add a whole new dimension to his combat skills.
If Naruto had Esdeath's powers, the plot would change drastically. Naruto's usual jutsu-based combat would be replaced by Esdeath's ice powers. His fights would be more one - sided as Esdeath's powers are extremely powerful. For example, in battles against Akatsuki members, he could freeze them instantly instead of engaging in long - drawn - out battles. Also, his relationships with his friends might change as his new powers could make some of them fear or envy him.
Tatsumi is very likely to be involved as he has a significant relationship with Esdeath in the original story. Her subordinates in the Jaegers might also be part of the fanfic. They could be shown as being protective or having mixed feelings about her pregnancy.
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.
A common power in fanfiction is enhanced magical senses. Characters can sense magic from far away, like being able to detect a hidden magical artifact from miles away just by the faint magical aura it emits. This helps in treasure - hunting type of storylines.
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.
If Naruto is Esdeath's brother in fanfiction, they could embark on adventures across different dimensions. Since Naruto has experience with his own world and Esdeath with hers, they could explore new lands together. They might encounter strange creatures and powerful enemies. Along the way, they could learn from each other's fighting styles and abilities, Naruto teaching Esdeath about chakra and she teaching him about her own brand of combat techniques. And they could also be on a quest to reunite their fragmented family or uncover a long - hidden family secret that has the power to change their worlds.
Well, their child might inherit Naruto's chakra control and Shion's unique spiritual powers. Maybe the child could have an enhanced form of the Rasengan, combined with Shion's ability to predict the future in a battle sense. For example, being able to foresee an opponent's moves just a split second before they make them and using that knowledge to adjust the Rasengan's trajectory for a more powerful and accurate attack.