One thing I haven't mentioned as I've been reviewing these Night of the Dragon books (Full Circle being the third and final installment) is that D.L. Moore passed away a few years ago, and since I don't know the circumstances, I don't know how much that affected the books. Full Circle in particular read very much like someone trying to provide a conclusion, without having the chance to build it up properly.
For example, at the end of the previous book, Jakes Giles leaves the group of people who have spirit-dragons. He thinks Eric is too unfocused and lacks a clear plan and Jake should be in charge. The fact Jake put on a second ring, and has two dragons in his head, has something to do with this. Initially in Full Circle, we don't see him, but when we do check in, we see he's hidden himself off in some frozen wilderness and is sending both the dragons out conducting his own searches for rings. He seems pretty determined to do whatever he thinks he must to prove he should be the boss. His first spirit dragon, Jak Oma Sall, seems less and less sure of what they're doing, while the second one, Loye Na Jil intensely resents being ordered about by a human. What's more, Jake seems unconcerned with anyone else's suffering, showing complete indifference when Loye destroys a village in Africa because one of his ancestors died near there centuries ago. To that end, his dragons attack one of the dragons in Eric's group and badly injure her (injuries inflicted on the dragon transfer to the person's physical body). But shortly after that, we're told Jake had a change of heart and rejoined the group.
Reading those sequences as they happened, it felt like such a waste. There were so many directions to go with it. Jake setting both dragons against Eric's group, or even Jake getting more rings and wearing them, with the resulting instability making each dragon a greater and greater danger. Jak could have tried to work with Eric's group against Giles. Loye could have found a way to defy Giles and fight all of them. As it is though, there's a brief squabble and he has a change of heart. It falls flat, and that seems to be because Moore didn't have time to really play it out, build the tension, then provide some sort of resolution. So that was a little disappointing because the potential was there for something very cool, but it didn't carry through.
Also, I found the repeated focus on using the spirit-dragons to find terrorists kind of awkward and uncomfortable. It seemed like an attempt to shoehorn a real world concern into a story where it didn't entirely fit. Especially in the latter two books, where Eric should be busy trying to stave off the destruction of the universe, but there's still lip service to trying to seek out and destroy terrorists. Have to prioritize.