I'm so interested in how The Mighty Nein show feels like a second draft to me. In like the sense that the campaign is your first draft that you discovery wrote. Which considering the improve nature of ttrpg storytelling, discovery writing is perhaps an good parallel.
In discovery writing you typically figure out the story as you go, not to say there isnt a plan, but it isn't intensely outlined leaving the author to make stuff up as they go. Plot and character voice tend to emerge over the course of writing. The trick is to then in subsequent drafts refine the stuff you came up with during writing to make the story support those ideas from the very start.
The somewhat meandering plot of campaign two is refined to focus more on the most compelling parts of the story overall (the war and Beacon) while still touching and establishing those important character bits that we had to wait a long time to have emerge in game.
Beau in the animation resembles a bit of her midcampaign self in her devotion to detective work while still keeping ideas of abrasiveness we see from the start of the campaign. The idea of who she would become is thus better implemented and seeded from the start of the story while also acknowledging her flaws. This still feels like Beau most importantly!
Likewise Essek was a character in game Matt intended as a villain but in the improve process that plan was changed to align with character actions. Thus the Essek we get in the "second draft" gets written from a place to seed what we know he will eventually become. He still does villainous things but his character is spelled out more and to prepare the viewer for his change of heart.
I dunno. I really like the show and I feel like most people dont acknowledge that the process of adapting an actual play is going to be vastly different from adapting a book for example. A book has already had its story edited and refined and drafted multiple times to be the best novel version of that story. Adaptation to the screen is then about making that story work for a different medium. Meanwhile an actual play is going to be an unrefined story that emerges through play, to adapt that you have to both do a second draft to refine the story AND make it work for a new medium.