Gulluvian Humans
by Marc SaindonGulluvia is a realm that, as written, runs a bit on fairy tale logic and tropes, so one suggestion is to develop humans along these lines to flavor the setting.
First thing, language. Due to contact to both Flaemish-speaking Elves (see my previous posts) and Averoignais-speaking Gnomes (another post, in which Dwarves get replaced), the halfway language that would develop between French and Dutch would probably be something akin to English. So Gulluvian Common is English. This ties in with nearby Glantri, who has an English-speaking population in Fenswick. Culturally, they would have something similar to Late Medieval Fantasy English culture, although they are permeable to foreign "Belgian" influences of the Elves and Gnomes in Gulluvia. Elven ancestry might also be common to many humans, who could display some signs of heritage without qualifying as Elves proper (the setting of Zelda comes to mind).
Another trait is alignment. Gulluvia is a high fantasy realm. Whether you call the world of faeries the 'Good Kingdom' or the 'Feywild', there is contact in Gulluvia between Mystara and the Fae World. Perhaps Gulluvia shifts into the Feywild in a cycle of seasons or even years (like Scotland's Brigadoon), leaving behind the desertic realm of the Adri Varhma Plateau in its absence. The fae energies have an effect on human passions: it polarizes people. Whereas in most kingdoms, your average peasant would be neutral or unaligned (he'll respect the laws of not murdering, but might cheat on his taxes to spare a few coins), in Gulluvia they are a bit more theatrical, with neutral alignments being rarer, and True Neutral being the rarest. Gulluvia doesn't produce Druids, it's a highly magical kingdom, not a sylvan one. Outsiders visiting Gulluvia might lampshade this on how people are bit more over-the-top than usual. The main polarization would center around Law versus Chaos (both as a call-back to the Basic D&D alignment system, and an attempt to split Seelie and Unseelie behavior along lines that don't concern good and evil), with "law" focusing also on proper etiquette, manners, protocol and customs. Lawful Mooks fight to the death to uphold their oaths more often than elsewhere, Chaotic Goons desert more frequently. Good and Evil are also affected (to a lesser degree), and expect villains and heroes to have showmanship.
(art from: https://www.deviantart.com/pretty-cool-huh/art/Quest-for-Glory-775031184)