The fifth of Stuart Grosse‘s Reborn as the First Boss novellas is almost stand-alone, focusing as it does on the elimination of an inquisitor squad. In a way it comes across as filler… despite not being any worse than the earlier entries.
Another series by the same author, albeit one of full-length novels, Winterborn resembles the above series. The key distinction is that while that is a story with RPG elements, this is more a novelized Icewind Dale campaign complete with positioning grids, fully transcribed dice rolls, and (in the later novels) hundreds of pages of character sheet.
The first three books cover a relatively low-level scenario focused on werewolves with the evil protagonist being of the ‘self-centered’ variety rather than the ‘slaughtering innocents’ variety. Of particular note is that while sexual topics/encounters come up from time to time, they don’t go into any detail. The second three then cover an epic-level campaign (following a time skip) and are much more like First Boss, with explicit sex scenes and a shift toward conquest on a societal level.
Overall I enjoyed the series quite a bit, with only two things in particular being annoying. The first is that the fifth book (Invader) in general is by far the weakest. Both because that’s where the explicit sex starts spontaneously popping up and because there’s an entire chapter devoted to, of all things, FFXIV fanfiction. The second annoyance is far more minor: We never see the reactions of the Dale tribes to any of her actions. While it’s fairly fitting for a D&D campaign to kind of ignore the PC’s backstory… it ends up feeling like a loose end.