There is literally zero need for the great curse.
I will give essence one thing and it is that it has a good idea to encourage Solars to extremes without it by giving them extremely potent powers that lock them in to their intimacies and virtues.
All you need is to have interesting secondary effects for the powers of the exalted fore example encourage Solars to become extremists, Lunars to gain derangements or would zones, Infernals to infect reality with demonic influence, Abyssals to bring unintended death and shadow lands and sidereals I dunno what could work for them.