What are the invocations and how will they affect the raid's difficulty? At the highest end, how hard can it get?
Before entering the raid you’ll be able to activate any number of invocations. Each invocation enabled will change the difficulty of the raid in some way. For example, a very basic invocation might give bosses more health or increased damage. You’ll be able to use these to tailor the difficulty of the raid to your liking, with loot scaling based upon the invocations used.