@ozeroz I read a lot of guides and watched great fights related to Castle Nathria. In my opinion and from what I have seen, there are two variants:Vengeance Demon Hunter and Protection Warrior Vengeance Demon Hunter and Brewmaster Monk
Demon Hunter - imposed on the boss Chaos Brand debuff which increases magic damage received by 5% it is also very mobile and highly durable
Protection Warrior is very good at dealing with physical injuries. Has the ability to buff a group that increases attack power
Brewmaster Monk put on target Mystic Touch increasing Physical damage taken by 5%. Stagger is also very useful and works very well in phases where the tank takes the most damage from the boss.