We all know kiera got hit pretty hard by the nerf hammer (with the magic resistance DEF gives) but instead of trying to mitigate the damage done and potentially messing up again, I was thinking that the developers could give her (as well as non-PVP oriented heroes) a niche by making her a must-use hero (or mystics at least) for what I'm about to suggest - the raid boss mode. I know the developers already have something similar planned, so I wanna provide some details that could make up for the shortcomings suffered by the less popular heroes in the arena.
The raid boss (be it dragon or phoenix or whatever) would be a permanent addition(not just an event) to the game modes available but can only be attempted 3 times a day. It would occupy a tile-size of 3X3(affected by cleave/splash damage but not thief's multiple hits), and would feature high DEF(to minimize champion's advantage they already own in the arena), 0 MAG and high single-target ATK damage but can be taunted.
Rewards would be weapon or armor fragments that could be used to craft high-tier weapons/armors (5/6*; random or selected) but the number of times they can per crafted per month is limited. If player cannot finish the raid boss, allies could attempt to finish for a portion of the fragments depending on the percentage of damage dealt.
This would make Kiera a must-have PVE-oriented hero for this raid boss mode with her massive AOE MAG damage, and with it being taunt-able, Darrion, a unpopular PVP hero as well, would be crucial to ble able to make full use of his high DEF to tank high single-target ATK. Ideally, this mode would be meant to allow non-PVP-oriented heroes to shine and players who are given these heroes not to be disheartened, knowing that these heroes serve a purpose.