Flame shield balancing problem

I want to report an unbalanced advantage of sorcerer which makes this class basically unkillable and very powerful in both PVE and PVP. It is unfair to other class and it is killing the game which makes many players left the game.

Below is the details how it works

One of the Sorcerer’s skill “flame shield” will provide immunity to the player which is very normal in the game. However, if a player equip Shako which CDR Crit, Pants, Chest armor and amulet with tempering “Flame shield duration”,flame shield duration can exceed 8 seconds. Exceeding 8 seconds should not be a problem until you equip Yen’s blessing boots. With this boot, sorcerer can proc flame shield automatically every 8 seconds. As a result, sorcerer is basically unkillable and it is breaking the balancing of the game. It has created a lot of frustration across the PVP community. Please remove the flame shield duration temper to fix this insanity