Sure is. Mysterio in the comics is known for being villainous. His powers of illusion are often employed for nefarious purposes and to oppose the forces of good.
A common 'villainous crossover fanfic' idea is to have the main villains from different fantasy series cross paths. For instance, Sauron from 'The Lord of the Rings' and Voldemort from 'Harry Potter'. They could exchange knowledge of dark magic and try to conquer both their respective worlds. Or, in a more comical vein, villains from animated shows such as Plankton from 'SpongeBob SquarePants' and Mojo Jojo from 'The Powerpuff Girls' could cross over. Plankton might try to steal Mojo Jojo's inventions to finally take over the Krusty Krab.
The use of multiple perspectives can also make the story in a 'villainous visual novel' engaging. By showing the events from the villain's point of view as well as the other characters', it adds depth. For example, we might see that the villain believes they are doing the right thing in their own world - view. This can create empathy for the villain in some cases, and at the same time, make the overall story more complex and interesting. Additionally, the setting and atmosphere of the visual novel can enhance the engagement. A dark, mysterious setting for a 'villainous visual novel' can set the mood and draw the reader or player further into the story.
One popular 'villainous visual novel' is 'Danganronpa'. It has complex characters, many of whom have villainous traits. The plot is full of twists and turns, making it an engaging visual novel experience.
To start a 'villainous crossover fanfic', begin by researching the villains you want to include. Know their personalities, motives, and powers well. Let's say you want to cross over the Joker from Batman comics and the Queen from 'Snow White'. You need to understand how the Joker's chaotic nature and the Queen's vanity can interact. Next, decide on the tone of your fanfic. Will it be dark and serious or more light - hearted? Once you've decided that, start writing the opening scene. It could be a meeting between the villains, or a situation where one villain discovers the existence of the other.
The main character is obviously the one who adopts the villainous dad. This character is often portrayed as kind - hearted and brave, willing to take on the challenge of having a villainous figure as a family member.
Another possible plot is that the main character discovers some secrets about the villainous dad's past that led him to be the way he is. This could lead to a journey of understanding and forgiveness, and also put the main character in difficult moral dilemmas as they try to balance their loyalty to their adopted dad with what is right and wrong.
The world - building in 'Villainous' is quite rich, and fanfic authors can expand on it. They can create new scenarios, new relationships between characters, and new plotlines. For example, they might explore how a villain would react in a situation that was not shown in the original series. This adds a whole new layer of depth to the 'Villainous' universe.
Well, you could write a fanfiction where the villains from different eras of the Harry Potter world team up. For example, Grindelwald and Voldemort joining forces in an alternate timeline. It would be really interesting to see how their different styles of dark magic would combine and how the heroes would deal with it. You could also focus on a single minor villain like Pius Thicknesse and expand on his character, perhaps giving him a more complex motivation for joining the Death Eaters than what was shown in the books.