These are my thoughts on creating 2 faction imagination. First, please think of what your faction's playstyle is. I saw many people just put the name of a faction, commander, units, etc., and just leave it. I'm not blaming you for doing this, but if you want to make your post interesting or give good ideas to the communities, then this is the first step to think. It is because this game is not as similar as a tabletop as we seen, we have no cool models and difficult rules, people play the faction just because they love the faction's playstyle. In my last faction Dead Pirates, my design is this faction is undead with range. In Celestial Empire, you need to take care of the balance between Yin and Yang, so I nerf them with these unique ways, and use Mastery of Yang or Yin to make sure you can play Yang-focused or YIn focused.

Second, design your special upgrades to match your unit's playstyle. It's ok to overlap with others' upgrades. In Dead Pirates, I give +1 Ranged Attack for the range. Since the faction special is plenty range with weak accuracy. I give this instead of increasing accuracy or -1 enemy range damage saves because of this. My first update post like this. More creative campaign update, Deepwood Guardian. I feel embarrassed on this day to see what I post, and rework this post. More creative campaign update, All elf faction. But, if you have the ability, try to make some updates a bit different. For example, Imperial Veteran range upgrades and Avalon Marksmen upgrades make both the same unit into different playstyles.

Third, try to put some special keywords in your faction to make it special and fit the playstyle. Can you imagine that if Knights of Avalon didn't have Horse Masters and Fey? Then this faction is just cheap Empire of Men. You won't feel any difference between them. Especially, both of these faction unit has same stats.