IMO, the main reason Knight and Chosen are the most popular tank is due to their auras (and mostly Resistance Aura). Then i propose a different system for aura.
New mechanic for auras :
Knight can have 3 active auras.
Auras affect Knight anytime.
Auras only affect allies/foes within 100 feet who have a Myrmidia's Will buff/debuff.
Knight have a new skill :
With that system, knight can't be offensive AND defensive with his auras, he has to choose if he want to buff allies (and what kind of allies) or debuff foes.
If i'm correct, auras buff (Blessing) can be cleanse by Chosen.
If i'm correct, auras debuff (Curse) can be cleanse by Shaman/Zealot.
Spoiler:
Examples :
See picture in spoiler :
1. Knight is offensive and go in melee with allies, using the new skill will buff close allies and debuff close foes. Healers and ranged allies and foes will not be affected by Knight's auras if they have a good placing.
2. Knight need to back to def healers, melee allies will not be buffed anymore (and remember it has a cooldown of 10s. You cannot buff/debuff anyone anytime)
Spoiler:
Miscellaneous :
If we want to prevent double Knight : People can only be affected by a maximum of 3 auras (so the auras of the closer knight).
Is it still too much powerful ? Then we can adjust cooldown and duration (as increasing cooldown or decreasing buff/debuff duration, but remember with that system aura buff/debuff can now be cleanse), number of feet, AP cost.
With that kind of system we can also do a new stat for kotbs/chosen piece bonus (if needed) like :
(X Piece Bonus): + Y seconds to Myrmidia's Will duration
