A plot could involve Baldur being sent to the realm of God of War by Odin to spy on Kratos. However, Baldur is intrigued by Kratos' strength and his relationship with his son, Atreus. Baldur starts to question his own loyalty to Odin. Meanwhile, Kratos is suspicious of Baldur but also sees a bit of his own past self in Baldur's blind obedience to a cruel father figure. Eventually, they work together to resist Odin's control over Baldur.
Perhaps in the fanfiction, there could be a magical accident that fuses the two universes. Baldur and Kratos find themselves in a strange new world that is a mix of their own. They have to rely on each other's skills to survive. Baldur's invulnerability and Kratos' combat experience make them a formidable team. Along the way, they meet characters from both universes and have to navigate political intrigue and battles, all while trying to find a way to separate the two universes again.
Odin could be the main antagonist. He is a powerful and manipulative figure in Norse mythology. He might see Kratos as a threat to his power and send Baldur to deal with him. But in reality, Odin could be using both of them for his own dark purposes, like obtaining some powerful artifact or spreading chaos in the realms.
One idea could be Kratos arriving in the RWBY world and getting involved in the fight against the Grimm. His combat skills and Spartan rage would be a huge asset. Maybe he teams up with Ruby and her friends, teaching them some of his more brutal combat techniques.
One possible plot could be that Kratos, from God of War, somehow ends up in the Assassin's Creed universe. He teams up with an Assassin, perhaps Ezio. Together, they face a common enemy that threatens both their worlds. This enemy could be a powerful Templar who has acquired some of the dark magic from Kratos' world.
Another possibility is that there is a new threat that emerges from the combination of the two universes. Some sort of evil entity that has the powers of both the Naruto universe, like the ability to use chakra, and the dark magic from the God of War world. Naruto and Kratos would have to learn to trust each other quickly in order to stand a chance against this new foe. They might start off at odds with each other due to their different backgrounds and fighting styles, but eventually realize that they need to work together.
One possible plot could be that Kurosaki Ichigo from Bleach somehow gets transported to the world of God of War. He might team up with Kratos. They could face off against a new threat that combines the Hollows from Bleach and the monsters of God of War. For example, Hollows with the strength and brutality of the Cyclops. Ichigo's Zanpakuto skills would be interesting to see combined with Kratos' brute force combat style.
A God of War 4 crossover fanfiction could involve crossing over with the DC universe. Kratos could find himself in Gotham City and have to deal with the likes of the Joker and Batman. His no - nonsense attitude and brute strength would be a contrast to the more morally complex characters in the DC world. Or perhaps a crossover with the Legend of Zelda series, where Kratos and Link could exchange combat techniques and embark on a joint adventure.
One idea could be a crossover with Norse mythology outside of the God of War series. For example, Kratos could meet Thor from the original Norse tales. Another could be a crossover with Greek and Roman mythology, where Kratos encounters some of the forgotten or lesser - known Roman gods. Maybe a crossover with a popular fantasy world like Middle - earth, and Kratos has to face off against some of the powerful beings there.
A crossover with another popular action - adventure game like 'The Witcher'. Geralt and Kratos could meet in a world that is a blend of their two universes. They might initially be at odds due to their different moral compasses, but then find common ground in fighting a powerful, otherworldly enemy that neither could defeat alone. This would create an interesting dynamic between their combat styles and personalities.
A cool Baldur's Gate crossover fanfiction could involve the world of 'Final Fantasy'. The different races and magic systems could create really interesting scenarios. For example, a chocobo could be introduced into the Baldur's Gate world. Also, a crossover with 'Star Wars' would be fascinating. Picture a Jedi - like character from Baldur's Gate using the Force in a different way, or a Sith - like character causing chaos in the Forgotten Realms. And don't forget a crossover with 'The Elder Scrolls', where the two very different magic and lore systems collide in interesting ways.
Well, it could be that Kratos discovers Pokemon in his journey. He might initially be confused but then realize their potential in combat. The Pokemon, on the other hand, would be in awe of Kratos' strength. Maybe some of the God of War monsters start to have Pokemon - like abilities due to some magical cross - over event, leading to a whole new set of battles and power dynamics.