Another interesting one is 'SNK and Harry Potter Crossover'. It imagines the characters from SNK in the magical world of Harry Potter. How would Eren and his friends deal with magic and Hogwarts? It creates a whole new and exciting story line.
One common theme is power struggle. When characters from different universes meet in a crossover, they often have different levels of power. For example, in a crossover with a superhero universe, the SNK characters might have to deal with the much greater powers of the superheroes, leading to a power struggle.
Sure. You can try searching on Archive of Our Own (AO3). There are often many fanfics with unique and cryptic themes related to SNK there. Just type in 'cryptic lover snk' in the search bar and you'll likely find some interesting reads.
One idea could be creating a male OC who is a skilled fighter in the SNK universe. He could have a unique fighting style that combines different martial arts techniques seen in the series. For example, he might blend the fast - paced attacks of Levi from Attack on Titan with the brute strength of some of the Titans. Another idea is to make an OC who is a strategist. He could be part of a military unit and be known for coming up with clever battle plans that turn the tide of difficult fights. He could have a backstory that led him to develop such strategic thinking, like growing up in a war - torn area. A third idea is an OC who is an inventor within the SNK world. He creates new weapons or gadgets that help the protagonists in their battles. His inventions could be based on the existing technology in the SNK series but with his own unique twists.
One popular 'hitman crossover fanfiction' could be the ones where Hitman crosses over with Assassin's Creed. In these, you often see the two different assassin - like characters interact, with their unique skills and moral compasses clashing or aligning in interesting ways.
There's a 'felicity crossover fanfiction' called 'Felicity Meets the Legends'. In this one, Felicity somehow gets involved with the Legends of Tomorrow crew. It's interesting to see how her character interacts with the time - traveling misfits. Her logical thinking clashes and also blends well with their more chaotic ways.
One interesting arcane crossover fanfiction is 'Arcane Meets Harry Potter'. It creates a really unique scenario where characters from Arcane enter the magical world of Harry Potter. The author does a wonderful job of blending the different magical elements and cultures from both universes. It's full of unexpected twists and turns as the characters from Arcane adapt to the new and strange world of Hogwarts and the wizarding community.
There's also 'Mentalist and Supernatural Crossover'. This fanfic brings in elements from 'Supernatural'. It has the characters from 'The Mentalist' getting involved in a case that has a supernatural twist, which makes for an exciting read as they try to figure out things beyond the normal realm of crime - solving.
One great 'the incredibles crossover fanfiction' is the one where they cross over with the 'Big Hero 6'. It's really interesting to see the Incredibles' superpowers interact with Baymax and the gang's high - tech gadgets.
One place to find valerian crossover fanfiction could be Archive of Our Own (AO3). There are often various fanfics that combine the Valerian universe with other elements. Just search for 'valerian crossover' on the site, and you'll be presented with a list of available works.
One great Starscream crossover fanfiction is 'Starscream in the DC Universe'. It's really interesting to see how Starscream's character adapts to the DC world with all its heroes and villains. His complex personality adds a new dynamic to the existing DC storylines.