Northern Hunters are humanoids covered in black fur with ram-like horns and long snouts. They have sharp teeth and claws. They have four tribes with distinct strengths and weaknesses, and usually fight among each other. When there is a threat that threatens all of the tribes, though, they unite to take it out. All Northern Hunters wear skulls as masks to strike fear into their enemies.
Picture - https://www.deviantart.com/rrdinoproductions/art/Axeman-719828679
Xoritians are lizard-like, their skin usually a shade of red. They have spikes running down their backs and three-clawed hands and feet. They are warriors, trained from age 9. They use weapons such as swords and spears to fight against enemies. They are allies with the Dragons, since they fear them.
Picture - https://www.deviantart.com/rrdinoproductions/art/Attack-on-Xoritian-Clan-Village-730141371
The Dragons are, well, Dragons. They are a jumble of different types of dragons, from hydras to wyverns. Only families share the same appearances. They are immensely powerful in battle, so nobody tries to battle them. The Dragons, though, try to be peaceful and settle things diplomatically.
Picture - https://www.deviantart.com/rrdinoproductions/art/Attack-on-Dragon-Rivine-703547621
The Guardians are the cooperation of humans and Diamondheads. They have the most advanced technology, but don't share it with the other empires in fear of them using the technology to fight each other. The other empires don't know about most of the technology they create.
Picture - (Bottom left is a Diamondhead) https://www.google.com/search?q=Eightmarn&rlz=1C1CHBF_enUS807US807&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjy6srjjMPcAhWNVN8KHZUHADUQ_AUIDCgD&biw=1920&bih=974#imgrc=v8EPjJsJRaVv4M: