The Kislev Empire
Kislev was founded years after the end of the Solaris War in Episode IV, by a person whose name we do not know. ^.^ In fact, we know precious little about Kislev at all. Judging by its capitol, they're more industrialized than anyone but Shevat or Solaris, and the presence of part of the Yggdrasil IV lets us know that they have not always been at war with Aveh, and in fact may have been allied with the Fatima family in the past. The Kislev area may have been involved in the war, but there's nothing to say either way.
Leadership: Kaiser Sigmund
The war with Aveh started two hundred years after Kislev's founding for an unknown reason. They gained an edge in the war with their tendency toward heavy-handed weapons technology - maybe through the intervention of Solaris. (I can't see them being thrilled that Roni started his own little club down there in the desert. ^.^) The Goliath seems to be the pinnacle of their achievements in that area.
Kislev is ruled by a Kaiser, and spans most of the northern region of Ignas. Nortune is a landmark not just because it is the capitol, but also for its battling tournaments. There are no other cities that we know of, but I'm sure they exist somewhere.
Sorry, Kislev fans. There's not much to say here. ^.^ Except that their symbol brings communism to mind. Don't ask me why. Probably because it looks like a work tool.