What are your thoughts on the Illrigger homebrew class?

The DM requires that our characters are good aligned.
I played the prototype of this campaign with this DM 3 years ago, so I know that we are forced to join a positive cult at the start and over the course of the campaign we learn that the cult is actually bad, and the big bads are the highest ranking members of that cult.
So it will be very easy to flavour the Illrigger's features as being blessings of the cult.

My main concern is that the class is either annoyingly complicated or unbalanced.