The ending of Jujutsu Kaisen Season 2 in the manga is a bit tricky to pinpoint. It depends on the author's storytelling pace and plot developments. Keep an eye on manga updates to find out.
The end of Jujutsu Kaisen season 1 in the manga is a bit hard to pinpoint exactly. It depends on which plot points you consider as marking the end. Generally, it's around a certain major event or climax in the story.
It ends at a specific point in the manga storyline, but it's a bit hard to pinpoint exactly without looking at the chapters. You might have to do some digging or check with fellow fans.
Jujutsu Kaisen Season 1 wraps up near chapter 63 of the manga. The anime does a decent job of keeping in line with the manga's storyline, but there could be minor differences in the presentation and pacing.
Yuji Itadori could still be the main character. He might have developed new and more powerful techniques in this fanfiction, and be the one leading the charge against new threats in the future of the Jujutsu world.
Maybe in the fanfiction, the story focuses on a character from the future coming back to the present in 'Jujutsu Kaisen Watch the Future'. This character has knowledge of future events that could either save or destroy the current world of Jujutsu sorcerers. The main characters then have to decide whether to trust this person and how to use the information without causing chaos.
The Jujutsu Kaisen manga is indeed ending. It's been a great run, but all good things must come to an end. The final chapters are bringing closure to the characters and story arcs.