Due to the unique HP system of the enemy "The Severed Warden," auto-aim abilities, like Mesa's Peacemaker, Protea's Blaze Artillery, and Xaku's Grasp of Lohk incorrectly target the body of said enemy, therefore most of the time not taking any damage. The only occasion this isn't a problem is when the damageable limbs of The Severed Warden are between the body and the direction from where the damage is coming from, taking the hit instead of the body.
In the worst case scenario, The Severed Warden can tank all the intended damage, guarding the enemies behind it and nullifying the effectiveness of said abilities.
The 2 possible changes to this could be either to change the targeting system to actually go after the limbs instead of the body, or make the enemy completely untargetable by said abilities, so that they would go after enemies that are actually vulnerable.