In fanfiction, 'naruto is the second god of ishgar' could mean that Naruto has been incorporated into the Ishgar setting and given a divine status. The 'second' part might suggest that there is already one main or more powerful god in that fictional world, and Naruto is just below in terms of power or influence. His skills and traits from the Naruto series are likely to be reimagined in the context of Ishgar, perhaps with some new abilities or relationships based on the rules of the Ishgar world.
There's no way to know for sure who specifically created this concept without more research. It could be a relatively unknown fan who just wanted to combine two things they liked. Maybe it started as a small idea in a fan community and gradually spread. There are so many fanfiction writers out there that it could be someone from anywhere in the world with access to both Naruto and Ishgar media.
We can expect more of the unique story elements that the series is known for. It might introduce new characters or expand on the existing ones. There could be new shadowy plots and unexpected twists.
One alternative could be a scenario where Morgana and Merlin are rivals in a magical tournament. They compete with their wits and magic skills, without any inappropriate content. Another could be a story where they have to team up to save Camelot from a dark sorcerer. They start off distrusting each other but gradually learn to work together.
Common themes include identity. The criminals may have a distorted sense of self or be hiding their true identity. Guilt is another theme. The psychological burden of guilt can be explored, whether it's the guilt of the criminal or the false guilt that others may feel. And the theme of psychological games. Criminals often play mind games with the investigators or their victims, like in 'Gone Girl' where the characters are constantly playing games with each other's minds to achieve their own ends.
The Winter Soldier could be an interesting character to introduce. He has a complex history with Black Widow. His presence could add more depth to the story as he might be forced to choose between his loyalty to Black Widow and his own conflicting motives. Also, his combat skills and his own history of being brainwashed could create some interesting parallels with Ultron's attempts to manipulate Black Widow.
One great 'lily and james potter fanfic' is 'The Potter Legacy'. It beautifully portrays their relationship and the challenges they might have faced. The characterizations are on point and it adds a lot of depth to the Potter family's backstory.
Vincent van Gogh. His life was full of passion and struggle. He painted some of the most iconic paintings while in a state of emotional turmoil. You could tell about his time in Arles, France, where he created many masterpieces. His relationship with Paul Gauguin, which ended in a rather dramatic way. His love for the local cafes and bars where he might have gotten drunk and found inspiration for his art. It's a story that has both the beauty of his art and the drama of his life.