Obviously Discord himself is a very popular character to feature. His chaotic nature and powerful magic make for interesting storylines. Pinkie Pie is also a common choice as her zany personality can either clash or complement Discord's chaos in really fun ways.
Fluttershy is another popular one. Given her gentle and timid nature, her interactions with Discord can be really sweet and endearing. Discord might be softened by her kindness, or he could playfully tease her, leading to some really charming scenes in the fanfiction.
Twilight Sparkle is often included. Since she's the studious and powerful unicorn, her reactions to Discord's antics and attempts to reason with him can be great plot points. Rainbow Dash, with her bold and competitive nature, can also create exciting dynamics when paired with Discord.
Ash Ketchum from Pokemon is a common character in these crossovers. He's a Pokemon trainer, and in a crossover, he could come to the world of MLP and start showing the ponies about Pokemon training. On the MLP side, Rainbow Dash is popular. Her adventurous and competitive spirit would make her eager to try out Pokemon battles or learn about different Pokemon species. So, a story with Ash and Rainbow Dash could be full of action and excitement.
Definitely Twilight Sparkle. Her studious nature and powerful magic would create an interesting dynamic with Discord's chaos. She'd be constantly trying to analyze and fix whatever Discord has messed up. Pinkie Pie is also great. Her zany personality could either match Discord's chaos or be a source of irritation for him. Rainbow Dash would be cool too. Her bravado and flying skills could be put to the test when Discord throws up some wild obstacles in her path.
Twilight Sparkle is really popular. She's smart and her magical abilities always add an interesting element to the story. Also, Sunset Shimmer is a favorite. Her backstory and her journey from being a bit of a villain to a hero make her a great character for fanfiction. Rainbow Dash is also popular, with her athleticism and competitive spirit fitting well into the Friendship Games setting.
John Koenig is often a popular choice. His leadership skills and complex character make him a great fit for crossovers. He can interact with other strong leaders from different sci - fi shows and create interesting power struggles or alliances.
Monika is often a popular choice. Her strong - willed and somewhat controlling nature can make for interesting crossovers. She can be the one who tries to manipulate the new world or characters she's crossed into. Sayori is also popular. Her bubbly and at times sad nature can add a lot of emotional depth to crossovers, especially in more light - hearted or heart - wrenching scenarios.
Loki is often a popular choice. His ability to deceive and his stealth capabilities can create really interesting plotlines in crossovers. For example, if crossed over with a detective - themed universe, Loki could be the elusive criminal that the detective characters are trying to catch, using his Warframe skills to outwit them.
Ikaris is often a popular choice. His flight and laser - eye powers make him a formidable character in crossovers. He can easily be paired with other flying superheroes or those who can withstand his powerful attacks. Sersi is also popular. Her ability to transmute matter gives her a unique edge, and she can be interestingly paired with characters who have different elemental powers.
Spyro is always a popular choice. He's one of the most well - known Skylanders and has a rich backstory that can be easily incorporated into crossovers. For example, he could be the leader of a group of Skylanders from different areas coming together.
Krawk is a popular character. It has a cool and somewhat menacing appearance which can add an interesting dynamic in crossovers. Another is the Shoyru. It's dragon - like and can bring a sense of magic and power. The Lupe is also often used. It has a wolf - like appearance and can be portrayed as a fierce and loyal character in crossovers.
Master Chief is definitely one of the most popular. He's the face of the Halo series, so fans love to see him in crossovers. Cortana is also a popular choice. Her complex character and her relationship with Master Chief make for interesting crossovers. The Arbiter is another character that often features. His unique backstory and his role in the Halo universe can add a lot to a crossover story.