An OC that is a reformed enemy could be really cool. For example, a character who used to work for one of Sly's nemeses but saw the error of their ways. Their knowledge of the enemy's lairs and plans could be a great asset to Sly's team. They would also have to earn the trust of the gang, which could create some interesting storylines.
Create a strong plot that involves both Sly and the OC. It could be a mission they go on together, or a mystery they have to solve. Also, don't forget the relationships. Show how the OC interacts with Sly and his friends. Are they friends? Rivals? Lovers? The dynamics between the characters are important for a good fanfic.
One popular Sheldon Cooper OC fanfiction might be those where the OC is a brilliant scientist who challenges Sheldon intellectually. For example, there could be an OC who has a different approach to theoretical physics and engages in intense debates with Sheldon. Another type could be an OC who is Sheldon's new neighbor and has to deal with his idiosyncrasies in a humorous way. There are also fanfictions where the OC is a love interest for Sheldon, but in a very unique and Sheldon - like way of falling in love, like through shared scientific interests and puzzles.
Since I don't know the specific Kaitlin Armstrong story, I can't say for sure. But generally, key elements in a story could include the main character's goals, the challenges they face, and how they overcome them. It might also involve relationships with other people in their life.
Perhaps the OC Guru is an old friend of Sly's father. So, he has a lot of stories and knowledge about Sly's family history. This could add a new layer of depth to Sly's character development as he learns more about his past through the Guru.
Think about their backstory. For example, if they grew up in a different part of the world from Sly, what kind of environment influenced them? If they grew up in a city full of traps and puzzles, they might be really good at solving those types of challenges.
To start writing a Sheldon Cooper OC fanfiction, begin with the OC. Develop their appearance, like what they wear, how they style their hair. This can give hints about their personality. Then, consider their field of expertise. If it's related to Sheldon's, great, but it can also be something different that still interests Sheldon. For the plot, think of a goal for your OC. Do they want to learn from Sheldon? Or do they want to prove him wrong? Once you have these elements, start writing scenes. Write how your OC feels when they first see Sheldon, what they think of his friends, and how they'll handle Sheldon's strict routines.
I'm not sure who exactly Alex Cooper in 'The Real Alex Cooper Story' is without more context. It could be an ordinary person with a unique story, or perhaps someone involved in a particular event or field.
Give the character a distinct appearance. For example, the OC Guru could have a long, flowing robe with strange symbols on it. And his eyes could glow when he uses his special powers.
Kaitlin Olson and Rob McElhenney's love story is quite charming. Their paths crossed on the set of the popular show. At first, they were just colleagues, but as they interacted more during filming, they realized they had a special connection. Their relationship wasn't rushed. It developed organically as they shared experiences, both good and bad, on set. Their love grew deeper, and they decided to tie the knot. Since then, they've continued to be a loving couple, and their relationship has added an extra dimension to their work on the show as well, as they bring the essence of their real - life love into their on - screen characters' interactions.