Wow, what a belated post this has become! I’ve been living in the area where Donnel’s speaking style is from for two years now!
As I have noted before, Donnel speaks with the sentence ending べ (be). This is the defining feature of the Tohoku dialect. The Tohoku region is made up of Aomori, Akita, Iwate, Yamagata, Miyagi, and Fukushima prefectures. In simple terms, the area of Japan’s main island that is north of Tokyo.
He also uses…
おら (ora) - I/me pronoun
おっ父 (ottou) - father
おっ母 (okkaa) - mother
…which are specifically characteristic of the more northern parts of Tohoku, as the further from Tokyo and the “standard” dialect you go, the more language differences you encounter.
Note that this is, of course, nowhere near the complete extent of the Tohoko region’s dialects. Characters usually only use very commonly known parts of different dialects so that every person who is fluent in Japanese can still understand them.
The Tohoku dialect has pretty much the same basic stereotype as the US Southerner accent: it means you’re a hick and others will probably see you as dumb and won’t take you as seriously. So fortunately, there was an English equivalent and this aspect of him did not have to suffer in localization.
Some photos I took today! Went on a long hike/walk around a forest area with a bunch of lakes/ponds! Super beautiful, perfect weather, nasty allergies, and now I am exhausted and satisfied. Can check today off my list of things to enjoy living through.