What to manage as a tank?

[CKNovel]

there should be phases tank loses the enmity for example "Rage mechanic"
where boss override and start aggro dps based on specific criteria..
tank has to knockout boss to remove rage ability
if tank do poor performance boss will attack hard hitting AOE till people to 130% of party HP.. if healers can't do it save it its a wipe

Already exist, in the form of "Interject".

O7S: An Add appears and if it's not killed in time it will wipe the raid. When it appears it cast Stoneskin that makes it unkillable if not interrupted.
E7S: Adds appears that must be grabbed by both tanks and moved along the arena. They cast Advent of Light that must be interrupted or wipe the raid.
DSR: Adelphel will cast Holiest Hallowing 3 times during the encounter, it must be interrupted or both bosses will recover all their health making the enrage unreachable.
87 dungeon: Final boss will cast "Bravery" that must be interrupted or it will boost its damages. Since it's a dungeon, it won't wipe the party.

Again, I encourage you to actually play the game as a tank before submitting feedback about a role you touch once every year.