I don't have the exact details on how far along the Persona 5 manga is at the moment. Usually, you can find this kind of info on official manga publisher websites or from manga enthusiasts' discussions on various online communities.
One Piece has been running for a long time and has made significant progress in the manga. But exactly how far it is depends on the latest chapters released.
The Haikyuu manga is quite far along. It has had many intense matches, emotional moments, and character-driven plots. But there's always room for more surprises and twists as the story continues to unfold.
The Demon Slayer manga has made significant progress and has completed a major part of its story. But specific details depend on the latest releases and updates.