I can't tell you much about this anime because I haven't seen it yet, I know it's been around for a while, but the truth is I don't feel attracted to it. However, the way you express yourself about it makes me curious, it seems to have a lot to offer.
Thanks for sharing with the community!
If you're not interested in the manga or just want to know what happens in the anime, I recommend watching the movie Gintama: The Final
This title is hypocritical because there are other movies like Gintama: The Very Final.