Obviously, Bro Strider himself is a main character. Often, his friends or family members might also be important characters. For example, if it's a fanfic about his younger days, his brother might be a key character.
Occasionally, Dirk Strider smiles in the comic. It's not a common occurrence, but when it happens, it's often tied to significant plot developments or emotional connections with other characters.
In terms of the plot of such a fanfiction, it could involve them teaming up against a common enemy. Maybe they have to face some sort of interdimensional threat. Their different abilities, Dave's with his time - related powers and Sans' bone attacks and teleportation, would make for an exciting combination in battle.
One great Bro Strider fanfic could be 'The Adventures of Bro Strider'. It really delves into his character, showing his cool and collected nature while also exploring his relationships. Another is 'Bro Strider: A New Perspective' which gives a different take on his role in the story.
Another common theme is the relationship between characters. In a crossover, Hiryu might form new alliances or rivalries. There could be a theme of trust - building or betrayal. Also, some crossovers might have a theme of self - discovery for Hiryu. As he interacts with new characters and situations, he may learn more about himself and his place in the greater multiverse of the crossover.
Another theme is discovery. As baby Dave grows and starts to show his unique personality, the other characters are constantly discovering new things about him. This can include things like his hidden talents or his strange quirks that are a hint of his future self. It's like they're uncovering the pieces of what will become Dave Strider as we know him in the original story.
One idea could be a crossover between Strider and a popular superhero universe. For example, Strider could team up with Spider - Man to fight a common enemy in New York City. Another idea is a crossover with a fantasy world like Middle - earth. Strider could journey with the Fellowship to defeat the Dark Lord. A third idea is a crossover with a post - apocalyptic world where Strider's skills are put to the test in a desolate landscape.
One interesting aspect could be those that explore Garrett Strider's backstory in the RWBY universe. Maybe he has a hidden past related to the Grimm or some secret organization. Another could be fanfictions where he forms an unlikely alliance with the main RWBY characters and they go on adventures together.
First, decide which two universes you want to cross over. If it's Strider and, say, the Matrix. Research both worlds thoroughly. Know the rules, the characters, and the settings. Then, come up with a plot that makes sense for both. Maybe Strider discovers the Matrix and has to fight the Agents. Next, start writing an engaging opening. For example, 'Strider was walking through an alley when a strange glitch in reality caught his eye.'
One common theme is adventure. Since Dave is from Homestuck, a story full of wild adventures, fanfics often involve the reader joining him on his quests. Another theme is friendship - turned - romance. They start as friends or allies and gradually develop deeper feelings for each other.