In the comics, John Constantine's sexuality is indeed shown to be bisexual. This aspect adds depth to his character and is part of his complex personality.
John Constantine in DC Comics is a master of magic and trickery. He's constantly dealing with demons and other supernatural threats. His character is a blend of bravery and cunning, making him a fan favorite.
There's a fanfiction where John Constantine crosses over with the Supernatural universe. It's really cool because it combines the dark magic and demon - hunting aspects of both worlds. Constantine's knowledge of the occult clashes and also meshes with the Winchesters' way of dealing with the supernatural, leading to some intense and exciting storylines.
Some of the best John Constantine graphic novels include 'Hellblazer'. It's a classic that delves deep into the dark and supernatural world Constantine inhabits. The stories are filled with complex characters and moral dilemmas.
The popularity of 'John Constantine Crossover Fanfiction' lies in the character himself. Constantine is a complex and morally ambiguous character. When he crosses over into other universes, it creates a lot of interesting scenarios. For example, in crossovers with superhero universes, his magic - based solutions contrast with the more traditional superpowers of heroes.
It could be a very intense love story. John Constantine is a complex and brooding character. The reader would likely be drawn into his dark world of magic and the supernatural. There would be moments of great passion, but also of danger as his enemies might target the reader to get to him.