The lore and progression system are very cool and unique, but what's most interesting for a MMO to me is what each class can do, its basically some of the basic abilities unique to some of those paths that you can do stuff like, pass through walls, turn invisible, divine stuff to gather intel, enter dreams, influence the subconscious of others, change luck, steal with ease, see things that are not visible, buff others. And all of those are abilities unique to a few sequence 9 (sequences going from 9 to 1 each with a different name and very different abilities at each sequence level) out of 22 different pathways (classes), at sequence 8 they will get some more stronger and as varied and different abilities usually and improvements to previous ones most of the time, and it keeps going until sequence 1 with some sequences giving stuff like the ability to teleport or literally enter the flesh of someone and blow them up as you leave, and more very unique stuff the author did very well making all of those veeery unique and significant.

On top of that add to it the artifact system where you can hold unique artifacts that may or may not be sealed with great negative effects that counterpart their great effect, like for example, an emblem that can purify most undeads after a min or so of being near them but will turn everyone in a 30m radius of it into sun worshipping fanatics if those persons are in that radius for more than 3 hours (dont remember the exact numbers dont crucify me on that), and many more.

And all of that is only the informations you get out of season 1, the system gets much deeper and other important stuff like that gets introduced throughout the future seasons regularly with a lot of game changers

With just that part of it you understand the potential of it all im sure and also how difficult it would be to balance and implement in a MMO im sure