First it was one system, then two, but now there are many systems tugging on Silas. He is borrowing power from anywhere he can get it including ancient primordial powers and uniquely human psi powers.
The question is whether he'll be torn asunder of forge a new type of Unity.
Unity is the first book in the new system, and although I disagree (almost entirely) with the description of the book here, Competing systems? (not really), just the new one in the world they went to after ascension, The whole mental thing, nope, not more than a single mention in the whole book. So, basically, ignore the description, and just read the book. It's well worth the read, especially if you're already liking the series, , just don't base your expectations on the book's description.
The demands of multiple systems pull him in different directions. Each wants him to serve them alone and drop his affiliation to the others. Some of the offers would tempt me.
But he does not want to play their game. He seeks to balance the systems inside him and be a free agent, able to use all his hard-earned abilities.
I enjoyed watching him be pulled around and respond. Seeing more points of view from enemies, allies, and family filled in some missing information, fleshing out the multiverse. This is a must read for those caught in the web of the series.
I had high hopes but this book was weak. Too much read like a text book. Too many times the MC did something dumb only to catch himself at the last second. In short, the hero was not a hero. AND, the endind was awful and I hate bad endings.