He could inherit some of the unique Uzumaki sealing techniques. Since Mito was an Uzumaki and was known for her sealing abilities, Naruto might be more proficient in that area. Maybe he could use seals in combat more effectively or create more powerful sealing jutsu.
Since Yoruichi has strong spiritual energy in her world, Naruto might inherit some form of enhanced chakra that has spiritual aspects to it. This could give him new jutsu or abilities that are a blend of his original ninja skills and this new spiritual - chakra power. For example, he could use his new power to sense things in a different way, like Yoruichi can sense spiritual presences.
He could inherit time - related powers. Maybe the ability to slow down or speed up time, which would be a huge advantage in battles. He might also be able to see into the past or future, which could help him in making strategic decisions.
He would probably inherit Wolverine's healing factor. So Naruto would be able to recover from injuries much faster. Maybe he could also have some form of adamantium - like bones or claws, which would be a really cool addition to his ninja skills.
One power Elena could inherit is Naruto's willpower. Naruto's unwavering will has been crucial in his many battles. Elena could have this same strong will, which would make her a formidable force against her enemies. In terms of more physical powers, she could potentially inherit the ability to use Rasengan. Although it might be in a different form in her world, it could still be a very powerful attack. Also, Naruto's ability to connect with others on a deep level could be passed down, allowing Elena to form stronger bonds with her friends and allies, which could be a power in its own right when it comes to facing challenges together.
She could inherit Naruto's chakra. This would give her an extra source of energy that she could use in combat. Maybe she could use it to enhance her physical strength like Naruto does when he taps into his chakra. Also, she might inherit his ability to perform the Rasengan. She could combine it with her sword - fighting skills for a really unique and powerful attack.
Naruto being Harley Quinn's son in this fanfiction could inherit a strange mix of powers. From Naruto, he could get the nine - tailed fox's chakra, which gives him immense strength and regenerative abilities. From Harley Quinn, he might inherit her skill with weapons like her mallet, but also her ability to adapt quickly in chaotic situations. This would be a really interesting blend of two very different power sets, allowing him to be both a strategic fighter like Naruto and a wild card like Harley Quinn.
He might inherit Naruto's shadow clone jutsu. This would be really useful for Markov. He could use the clones to gather information, fight multiple enemies at once, or even learn new skills faster by having the clones practice simultaneously. Also, Naruto's enhanced physical strength and speed, which come from his chakra, could be passed on to Markov, making him a formidable fighter in the fanfiction.
The baby could inherit Naruto's chakra reserves and his ability to use the Rasengan. Since Naruto has an enormous amount of chakra, it would make sense for the baby to also have a large chakra pool. The Rasengan is one of Naruto's signature moves, and it could be passed down genetically or through training that Naruto would give the baby as it grows up.
One possible plot could be that Naruto, as Mito's brother, discovers some long - hidden family secrets. Maybe he finds out about a special power that has been passed down in the Uzumaki family but was lost over time. He then embarks on a journey to rediscover this power and use it to protect the village in a new way.
She could inherit his ability to resist the Imperius Curse. This would make her more resistant to mind - controlling magic in the DxD world. Also, his skill in Defense Against the Dark Arts could translate into better combat skills against devils or other threats in her world.