It's a crude, juvenile isekai comedy. The baddies think the protagonist's name is "Virgin" (aka. "DT" or "doutei", which is Japanese for "male virgin"). DT sticks his private parts out of a window in ep.16, can't fight and is sometimes a scumbag (ep.8). The baddies' leader (Erec) loses his testicles from DT's attacks and doesn't tell his fiancee. A hot transvestite is female from the waist up and male from the waist down. (She chooses a gender in the last episode.) An elderly king is less senile than he looks, but has an incontinence problem.
The show's quite funny, but it's not closely wedded to its plot and sometimes got a bit pointless or even tiresome. The show's finale is more interested in making fun of cliches than in getting on with its story. It's the kind of show that even on the rare occasions when it tells a heartwarming backstory for one of our heroes, it'll probably all turn out to be lies. (DT's friends were pulling his leg.) I usually thought the show was okay. Occasionally I fast-forwarded through episodes. I won't keep it, but it's not too bad. You could give it a go and see if it's your cup of tea.
Our heroes are DT (mostly useless), Sainglain (a badass muscleman who loves small, cute animals), Mariandale (the aforementioned transvestite, with a multiple-choice voice) and Ecarlate Juptris Saint Piria (an eight-year-old princess who's travelling to get married to the adult Lord Nabokov Jugglaburk).
The show arguably has a second protagonist group, though, i.e. the elite knight group of baddies who have been ordered to stop Princess Ecarlate. That's Erec (who loses his -tion), Variation (said to be a sadist but basically normal), KT (drunkard who may or may not be secretly female), Gustave Gustaf (loves hostess bars) and Leon (masochist).
The plot's reasonably good, surprisingly. It's not the show's main focus, but it's a perfectly solid framework for 25 episodes. I also quite like the world. It's not just a generic RPG isekai and it's not leaning on pseudo-medieval historical stereotypes, although it does often rip off aspects of modern Japan for comedy. (Karaoke bars, for instance.) There are empires, countries, archbishops, international politics and an ancient lost race that lived in a flying city and had advanced technology. Surprisingly, the anime ends up never really doing anything with the latter. It's based on an online game by Capcom (also called Ixion Saga), so maybe some of this is just imported worldbuilding? It still feels more developed than a lot of straight anime, though, let alone pisstakes like this.
Princess Ecarlate I liked. She's the one who's calling the shots and stoically facing up to her impending marriage, despite being eight. She's the only one with genuine, non-comedic emotion in the final episode. Everyone else is either her enemy or her bodyguard. (Mind you, she does have a psycho mode that's triggered by hairs on her head standing up. Her effect on that assassin in ep.6 is extremely funny.) There's no one in the cast I disliked, though. They're all okay and have their moments.
The show's fine. Not great, but fine. You'll lose some of the vulgarity if you don't speak Japanese, but the subtitles do a reasonable job of compensating. ("Screw" as a translation for "hameru" works in both of the senses being used, for instance.) See also the theme songs about losing your virginity and about Erec's missing testicles. Also, despite being an extremely male show in its sense of humour, it has negligible fanservice and is actually putting far more male flesh on display. You could do worse.