I'm sorry, I haven't read the 'Wolverines Vol 1 20' specifically. But generally, Wolverine stories often involve his adventures, his battles against villains, and his complex relationships with other characters in the X - Men universe.
Well, in a fanfic where an OC has Wolverine's powers against the Joker, it could start with the OC being in Gotham. The city's dark and gritty nature would contrast with the OC's more animal - like and straightforward power set. The Joker would likely try to use the OC's short temper (a trait Wolverine sometimes shows) against them. Maybe he'd set up situations that would make the OC lash out and cause destruction, which would then turn the city against the OC, putting them in a tough spot.
It's hard to say for sure. If the author or creator has stated that it's based on real-life, then it might be. But often, stories like these can be a blend of reality and imagination to make it more engaging.
The OC would probably be initially enraged by the Joker's antics. Wolverine - like powers mean a short fuse sometimes, and the Joker's chaotic behavior would surely set that off. But as the story progresses, the OC would have to learn to control their temper to effectively deal with the Joker.
In a cheer competition, there was a story about a small team from a rural area. They had very limited resources but their spirit was high. They practiced day and night on a patchy field. Their story inspired many other teams to not be deterred by lack of facilities. They finally made it to the regional finals and won the hearts of the audience with their sincere and energetic performance.