Let me just start off saying that I am really enjoying the game. You have a good balance and plenty of content.
I only have a couple of recommendations or issues. The first is the design of some tanks. They fill a nice position in pve or pvp, some you need to ascend to get their taunt though. This should be their second skill and always available when you get them right after their basic attack. They shouldn't have high dps attacks, their taunt is their main role in either pvp or pvp. Pignius runes do not lend themselves to tanking very well maybe a change for him or adding a red bulwark rune to help him out. Instead of changing zens skills around you could have changed kozars home run attack to get rid of that weird dynamic that was dominating pvp.
My second issue is with rune stats. They are confusing and not explained well. Crit and skill doing the same function as well as damage and attack. Outside of boosting crit there is no way to increase healing spells. Skill should be changed to affect spell power and ranged attacks, attack should affect melee. Maybe take an option from wow and come out with combo runes that can fit in any of the base slots, like orange runes that can fit either red or yellow slots or purple that can fit blue or red. You get the idea.
Anyway thanks for taking the time to read this.