One great piece of Supernatural Dean Cas fanfiction is 'AUs Are Made of This' which offers a really interesting alternate universe take on their relationship. It's full of heart - warming moments.
Another theme is sacrifice. Given the nature of the Supernatural world, they often put themselves in harm's way for each other. Fanfictions play on this selfless aspect of their relationship. For example, Cas might sacrifice his grace to save Dean, or Dean might risk his life to rescue Cas. It shows the depth of their bond.
A 'cas visual novel' is typically a form of interactive fiction. It often combines text, images, and sometimes audio to tell a story. The player usually makes choices that can affect the plot's direction and the outcome of the story.
I'm not sure specifically about 'cas visual novel' titles being extremely popular. There are so many visual novels out there that it's hard to say if ones specifically labeled 'cas' are well - known without more research.
One great Cas Shields Constantine crossover fanfiction could be 'The Convergence of Worlds'. It combines the unique powers and personalities of Cas and Constantine in an exciting adventure. The story has a well - developed plot that keeps you hooked from start to finish.
Well, in many Cas and Dean first kiss fanfictions, it often occurs in a moment of high emotion. Maybe after they've just saved each other from a dangerous situation. The writers usually build up a lot of tension between them first. For example, there might be lingering looks and unspoken feelings for a long time before that first kiss. It's a way to explore their relationship deeper than what's shown in the original series.
One common theme is the revelation of hidden feelings. For a long time, they may have been suppressing their emotions for each other, and the first kiss is like the breaking of a dam. Another theme is the acceptance of a new aspect of their relationship. It's not just about being friends or hunting partners anymore. And finally, there's often a sense of new beginnings, as if this kiss opens up a whole new world of possibilities for their relationship.
A common theme is protection. Cas, as the 'daddy' figure, often protects Dean from various threats. Another theme is emotional growth. Dean might grow and develop in his relationship with Cas.