Rosen Garten Saga

Similar humor to prison school (but way more graphic) combined with outstanding art & battle scenes, with a heavy dose of narcotics. Genius. It weaves through fanservice, jokes and action seamlessly. The fanservice is basically hentai level so not for everyone. We are talkin’ men fighting with their dicks level of hentai.
For the serious parts: The plot combines a bunch of legendary mythos but mainly focuses on Nibelungenlied at the core. That area of legends isn’t touched on as much in manga so it’s refreshing to see. The additional mythologies mesh really well given how Nibelungenlied already has characters like atilla the hun. All of the heroes depicted are heavily parodied, and every weird attribute from their source material is amplified to be their entire gimmick.