Klaus Mikaelson could form an alliance with Daenerys Targaryen. Daenerys is known for being open to different beings and powers, and Klaus' strength could be of great use to her in her quest for the Iron Throne. Also, they both have a certain air of royalty about them.
He might team up with Tyrion Lannister. Tyrion is a very intelligent character who often has to rely on his wits to survive. Klaus' power could protect Tyrion, and in return, Tyrion could offer his strategic mind to Klaus. They could make a rather unlikely but effective duo in the cut - throat world of Game of Thrones.
He could potentially form an alliance with the Starks. The Starks value honor and loyalty, and Madara, with his own sense of loyalty to his own ideals (albeit in a rather extreme way in his original story), might find common ground. He could offer his combat skills to help them in their battles against their enemies. Another possibility is an alliance with the Targaryens. The Targaryens have a connection to magic and dragons, and Madara's own powerful and somewhat magical abilities could make for an interesting partnership. He might see value in their claim to the Iron Throne and support them in exchange for certain power and privileges.
Draco might form an alliance with the Lannisters. They are both power - hungry and cunning. The Lannisters' wealth and influence would attract Draco, and they might see his wizarding abilities as an asset. He could also form an alliance with the Tyrells. The Tyrells are known for their political savvy, and Draco could use their connections to further his own goals in Westeros.
In a Game of Thrones fanfiction with Klaus Mikaelson, his character would bring a whole new level of chaos. His immortality would give him an edge over most of the characters in the Game of Thrones world. He could play the game of thrones in a very different way. Instead of just vying for the Iron Throne, he might be more interested in creating his own empire. He could use his compulsion ability to sway people to his side, and his combat skills, which are enhanced by his vampire nature, would make him a feared opponent. His backstory of family drama could also be paralleled with some of the family feuds in Game of Thrones, like the Starks and the Lannisters.
Another possible alliance for Naruto in Marvel fanfiction could be with the Guardians of the Galaxy. His immortality would give him the confidence to explore the cosmos with them. He could use his chakra to help power up their ship or provide combat support during space battles.
Superman might also form an alliance with some of the more noble and freedom - seeking human kingdoms. These kingdoms might see him as a way to bring peace and stability to their lands. For example, if a kingdom is being attacked by bandits or darkspawn, Superman could quickly come to their rescue. In return, they could offer him a place to stay and resources, and together they could work towards a more just and prosperous Thedas.
Another possible alliance for the Spartan in Westeros could be with the Night's Watch. The Night's Watch is all about defending the realm from threats, and Spartans are all about defending their homeland. The Spartan's discipline and combat skills would be a great asset to the Night's Watch in their fight against the White Walkers. Plus, the Spartan might be drawn to the noble cause of the Night's Watch, which is to protect all of Westeros.
He could form some really interesting relationships. He might befriend the underdogs, like the Starks, and use his powers to help them. Or he could have a mentor - like relationship with someone like Tyrion, sharing his wisdom from his own world. He could also have an adversarial relationship with the more power - hungry characters, like Cersei, as his values would likely clash with hers.
The Sith might form alliances with the most power - hungry characters in Game of Thrones. They could ally with Ramsay Bolton, for example. Ramsay is cruel and power - thirsty, and the Sith could use his brutality to their advantage. They might offer him dark powers in exchange for his loyalty in their quest for control over Westeros.
Well, in the fanfiction, the baby could have some special powers. Since Klaus is a powerful vampire - werewolf hybrid, it's not a stretch to think his baby might inherit something extraordinary. The plot could revolve around Klaus trying to understand and control these powers in the baby. And perhaps there are other supernatural beings who either want to use the baby for their own gain or are afraid of the baby's potential, leading to a lot of conflict.
One great Klaus Mikaelson hurt fanfiction is 'Bleeding Hearts'. It shows Klaus in a really vulnerable state after a powerful spell backfires on him. Another is 'Broken Wings' where he gets physically injured during a fight with an ancient enemy and has to rely on his friends for help.