Want to make each faction more important/awesome/inspiring and easier to enthrall players?

Add voice actors for each god, and make more unique and individual characters.
Your Caos should have some sort of phisical mutation aflicted by his god (eg: cold vapors emanating from your body/ice spikes if you are Void and fiery footprints/smoke coming out of your armor if you are Dark) and you should be able to use breakables in your favor.
This would be unique for a free-to-play game, and it could make more players like this game, while Human/Caos scalling should be adressed (Humans seem absolutely worthless in combat).
About combat: Please, for the name of god, stop sending waves with just one single type of enemy and make each wave more diverse(eg: trolls with shields, they block most of your attacks and every one of their attacks makes you stagger, leaving you vulnerable. This means that when you are hit, half of your life is gone. This is also applies to Troll Bersekers, if you let only one of them hit you, you're pretty much dead.)
Although the combat is awesome, it has many flaws. I think that you should rethink how stagger works and improve upon executes (eg: All executes restore health; more execute animations for the other mobs; double, triple and even mass executes would be awesome and a higher stun chance. Also the level-up shockwave should not kill enemies, it should stun them, leaving them open for a mass execute)
Speaking of combat, I think you should add more weapon/armor/miscellaneous items into the game, thus diversifying combat. You should add shields, bows, daggers, staffs in order to implement (and encourage) diversity and more inmersion, adding even more flavour/sattisfaction to the combat system.
Here I will describe what I think each weapon should do:
-Staffs could reduce the cooldown of spells while also improving other features and spells (improved dashing and even teleportation). Staff wielders would have different bonuses depending on aligment. Void staff users would deal more damage but be more prone to stagger effects and have less health, while Dark staff users would be more beefy, while their spells would deal less damage but would work very well in conjucture with another weapon. Light would be a mix between the two.
Staffs would also add a mix of uitlitarian spells, like telekinesis (this could work well with breakables) and elemental bending (imagine rising a 2hit stone wall in front of a dashing player or traping a mob of enemies in a corner)
-Shield would block more powerfull atacks when raised, add more armor and they could work well with weapons with faster movesets
-Bows should fell just as brutal and satisfying as their male counterparts. These should stagger more, and you should be able to combine arrows with your faction spells, while also oferring more mobility (dash becomes a bigger jump?) (arrows should be huge)
-Daggers should land a dozen blows when a sword could land only one such hit. Poisons, chain traps, human grenades (throw it on an enemy and watch as he is hugged to death!) or other such effects. These could work well alongside a bow or a bigger weapon and should corespond to your alignment.

Once you are in combat you should not be able to check your inventory, but instead you should be able to quickly switch between your primary and seconday weapon (or even tertiary?).
Also, you should introduce ACTIVE PVP. An arena or an entire zone where you could battle actively between players would make the game seem way more alive. In each region, the players could have one certain zone or dungeon where the link between worlds would be so strong, that they would be able to fight eachother over humans, dominion, chests, and who gets to kill the boss of the day.

Since I mentioned humans, I think that the territory control should be expanded upon. You could add (humansized) siege weapons for the humans with quantity variations (Void towns would have a lot of siege weapons and also a small population, while humans in light towns would have be to busy breeding like rabbits to care about siege weapons. Dark towns would be a mix between the two, with the addition of jails and gallows.

Thanks for reading through :D