First of all I think the Life staff is in a fine position and does not need to be nerfed further. IMO that would just hurt PVE more than anything else. Everyone has seen the videos of a Life stuff user taking a beating from multiple people at once. Which again, I don’t think is the big issue. Yes it’s annoying, OP, what have you. However the main issue is, Life staff users are just not running out of mana, which allows them to pretty much stay alive indefinitely at times.
Here is my idea.
Every class has a mana pool regardless of if it’s used or not.
No class/weapon has a mana burning ability.
Remove any talent that gives Mana for successful blocking.
Add -mana to every attack by everyone.
-1 mana light attacks
-3 mana Heavy attacks
This simple change will still allow a Life staff user to wear heavy if they choose. Only they will no longer just be able to tank all the hits with no real downside. Sure they will still be “strong” in a 1v1, but to be honest, they should be, if you can not out heal the damage of 1 person, then healing in general is just pointless. However when hit by multiple people, which will always happen in a PVP situation. The mana pool will quickly start depleting, forcing them to run or die.
Anyways, that is just my idea, I think it strikes a fair balance between what both sides want.