Quote Originally Posted by Lyth View Post
Holmgang's root effect was coupled to a draw-in effect. This also had the unintended situational benefit of cancelling some otherwise uninterruptable mob actions. As a result, the effect was removed alongside all other player generated PvE draw-in/knockback effects in 5.0 (Blank Shot/Backdraft/Shockwave/Fluid Aura's knockback). Holmgang's recast was increased by a minute at the same time. The duration increased to 8 seconds in 5.1 and 10 seconds in 6.0.

Tank invulns are a textbook example of why partial homogenization is worse than complete homogenization. The more similar you make two actions, the easier it is to mathematically determine a clear winner. It's fine to want to preserve the 'flavor', but the spread of recasts is too big at the moment.
Gotta love how when faced with a problem like this they just make the entire game worse as a solution for no real benefit.