Survival is another theme. In Evangelion, humanity is constantly fighting for survival against the Angels. In Naruto, the characters also face various threats. Fanfictions may combine these threats, like having the Angels attack the ninja villages. This forces the characters to use their combined skills and resources to survive, leading to new character developments and interactions.
The Neon Genesis Evangelion manga has indeed finished. It reached its conclusion after a series of chapters and story arcs that wrapped up the plotlines.
Sure. You can start by looking on fanfiction.net. There are often some interesting crossovers there. Some fanfictions might focus on how the characters from Naruto interact with the complex world and mecha concepts of Neon Genesis Evangelion. For example, they could put Naruto characters in the Evangelion pilots' positions, facing the Angels with their own ninja skills.
Neon Genesis Evangelion's full story is about humanity's fight against the Angels. Shinji is brought into this battle reluctantly. The Evangelions are the only hope to stop the Angels from reaching Terminal Dogma. Along the way, Shinji forms relationships with other pilots like Asuka and Rei. The story also has elements of religious symbolism. For example, the Angels have names with religious connotations. The story gets darker as it progresses, exploring the psychological breakdown of the characters due to the intense pressure of the situation.
Sure! Neon Genesis Evangelion has a manga version. It presents the story and characters in a different format from the anime, but still retains the core elements that made the series popular.
Shinji is a great character to focus on. His complex personality, full of insecurities and self - doubt, offers a lot of room for exploration. Rei is also interesting as she has a mysterious past and her own identity issues. And then there's Kaworu, who has a unique connection to Shinji and his own enigmatic nature.