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.
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.
One common theme is redemption. Given Baldur's actions in the game, many fanfics explore the idea of him seeking redemption for his past deeds. Another theme is family, especially his complex relationship with his mother and how that influenced him.
Sure. You can check out fanfiction websites like Archive of Our Own. There are many 'god of war baldur fanfic' there. Just search for 'god of war baldur' and you'll find a variety of stories written by different authors, with different plotlines and interpretations of Baldur's character.
One of the most interesting aspects of a Perseus Jackson in God of War fanfiction could be his relationship with Kratos. Kratos is a complex and powerful character. Perseus, with his own set of values and beliefs, might either become an ally or an adversary to Kratos. They could learn from each other's combat styles and experiences, or they could be at odds due to their different views on the gods and their roles.
Arcanine. This majestic and powerful fire - type Pokemon has a look of a noble beast. In the God of War world, it could be seen as a symbol of power, like the mythical beasts there. It could use its fire attacks to fend off the hordes of demons and other enemies.
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.
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 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.
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.