I'll give it a try for the EU Kingdoms:
Nirath: The biggest and oldest kingdom on EU. They are quite inclusive, get along with almost everyone and feature large Spanish and German communities. They used to have a focus on a hot desert climate, but dropped that once it became clear Dragor would come in last at land selection, instead focusing on the community.
Arkadia They have the outward image of a generic medieval kingdom, even though they intend to aim for Greek/Roman culture. The kingdom appears to be mostly built on duchies focused on one language community. There's Italian, French, German, Russian, Portuguese and Spanish groups, but no numbers on the size of each.
Tryggr: The last of the three old kingdoms. No longer an official kingdom after they lost their layaway in recent events, but still one of the larger EU communities. Their theme is mostly inspired by vikings. Their general attitude can be described as either crude or honest, depending on your perspective.
Demalion: A relatively young kingdom with two royal pledges. The rulers are Arabic, but they recruited Terenia, a sizable EU community that lacked high pledges. Their aim is to establish an empire.
Al-Khezam: The youngest EU Kingdom. It came into existence after the Duke of one of the four big duchies of Nirath decided his philosophies differed too much from those of Nirath. Their general image is that of an Arabic culture and they strongly focus on equality and tolerance.