A chronological listing of Dumarest's interaction with the Cyclan and other pertinent details about them from the novels follows.

1. The Winds of Gath. Dumarest begins the series seeming to simply mistrust the Cyclan, their methods and their agenda because of their total lack of emotion.  By the end of the book he has spoiled one of their elaborate plots, they have attempted to kill him and he has succeeded in killing one of them.  Not exactly getting off on the right foot.
2. Derai. Cyber Regor accidentally kills the woman Dumarest loves (while trying to kill him).  Dumarest’s mistrust of the Cyclan had already evolved into active dislike in Book 1, The Winds of Gath, and now it turns to abject hatred.  On the other hand, the Cyclan almost certainly blames Dumarest for the loss of an important experimental subject, and while they’re incapable of hatred, this is still a major setback in their telepathy research program.
3. Toyman. Dumarest foils the Cyclan’s attempt to rub out their computational competition and ensures that they won’t get another chance, or be trusted on the planet Toy for a very long time.  If they were capable of emotion, they’d be starting to hate him as much as he hates them.
4. Kalin, Dumarest learns of the affinity twin and unwittingly takes receipt of the correct sequence to reproduce it, contained in the ring given to him by Kalin.  He doesn’t know it yet, but the Cyclan will pursue him relentlessly for the rest of the series because of this.  In hindsight, this is ok, because it will give him the opportunity to kill them by the dozens, a deed of which he will never tire because of what they did to Kalin.
5. The Jester at Scar. Earl becomes aware that the Cyclan desperately wants the ring Kalin gave him, but he doesn’t learn why.  Dumarest kills several Cyclan-hired thugs and eventually Cyber Yeon in self-defense when at various times they try to murder him and steal it.  In the process, he inadvertently spoils a Cyclan plot to extend their domination to the worlds Jest and Eldafane.
6. Lallia. Earl learns the ring Kalin gave him contains the secret to the affinity twin.  He also kills one of the Cyclan’s non-Cyber bounty hunters and steals the cash advance they gave him.
7. Technos Cyber Ruen endangers a plot already in motion so he can capture Duamrest.  Dumarest kills him for his trouble and exposes the Cyclan plot, ensuring that the new government of Technos will not fall under their influence (at least not in the near future).
8. Veruchia. Earl destroys the stone from Kalin’s ring containing the proper sequence to assemble the affinity twin.  That knowledge now exists nowhere in the galaxy but in his own mind, so the Cyclan will be saddled with the inconvenience of using non-lethal measures to capture him alive for the rest of the series.  Once again, Dumarest foils a Cyclan plot already in motion and avoids capture, but this time he doesn’t get to personally kill any Cybers (although he does kill an acolyte and Cyber Surat is killed in the firefight when Dumarest escapes).
9. Mayenne. By now the Cyclan has placed agents on every ship in the area in a dragnet for Dumarest, and unsurprisingly both of them who are on Earl’s ship end up dead.  The nearly omnipotent entity Tormyle’s casts Dumarest out of its domain at random, meaning the Cyclan has no way to extrapolate his movements and must start their search over from scratch.
10. Jondelle. No cybers or other agents appear in the book, although Earl does make sure the Cyclan has nothing to do with Jondelle’s strange lineage before agreeing to return him to his family.
11. Zenya. The main villain, Parect, is paranoid enough to realize that the Cyclan always have ulterior motives for the advice they give, and because of that distrust he uses their interest to manipulate Dumarest instead of accepting their first offer to hand him over.  Other than that, they do not directly appear in or influence the action.
12. Eloise, Except for the first chapter, told from the point of view of Nequal, the Cyber Prime, and included to provide the backstory on who Dumarest is and why he is running from them, the Cyclan otherwise don’t figure into the story at all.  In that chapter, however, we learn the significant detail that the older brains in the gestalt mind that comprises the Cyclan Central Intelligence are deteriorating and the Cyclan have no idea why.  We also learn that the search for Dumarest is being significantly intensified.  Fortunately for Dumarest, a freak accident throws his ship halfway across the galaxy midway through the book, so the Cyclan have no way to extrapolate his movements and once again have to start their search over from scratch.
13. Eye of the Zodiac. The Cyclan once again interrupt a plot in progress to capture Dumarest and fail, thereby blowing both missions.  Dumarest believes the Cyclan killed his protégé Leon (or at least spurred him into a suicidal act).  Dumarest kills an acolyte and rids the galaxy of Cyber Hsi (without stopping his heart) by use of the affinity twin. 
14. Jack of Swords. Dumarest avoids capture by the Cyclan or their agents several times, and they are involved in the main villain's backstory, but they do not otherwise figure prominently in the plot.
15. Spectrum of a Forgotten Sun. Although no Cybers appear in this story, the entire novel is based on the failed attempt of one of the Cyclan’s human agents to keep Dumarest in one place long enough for them to come collect him (and surprise, surprise, she dies).
16. Haven of Darkness. Cyber Broge kills Dumarest’s friend Armand, frames Dumarest for the murder and eventually captures him.  Dumarest escapes the Cyclan’s clutches again, killing Cyber Broge and his acolyte in the process.
17. Prison of Night. Dumarest spoils the Cyclan’s chances of bringing Zakym under their influence (although that goal was merely an offshoot of their attempt to capture him) and brings about the death of Cyber Ardoch.
18. Incident on Ath. Dumarest escapes a Cyclan dragnet on Juba, but does not directly interact with any Cybers or other Cyclan agents.
19. The Quillian Sector. Dumarest kills an acolyte, causes injury to Cyber Caradoc and escapes again.
20. Web of Sand. Cyber Tosya concludes incorrectly that Dumarest is dead and calls off the search.
21. Iduna's Universe. The Cyclan still believe Dumarest is dead, so no Cybers appear in the story.
22. The Terra Data. The deterioration in the Cyclan's Central Intelligence, first revealed in Book 12, Eloise, is getting worse.  Dumarest is largely responsible for Nequal, the Cyber Prime, being terminated and replaced by Elge.  Unfortunately, Nequal’s final act of deduction informs the Cyclan that Dumarest is still alive and most recently on Elysius. 
23. World of Promise. Cyber Okos, while in rapport with the Central Intelligence, is contacted by the afflicted brains and is driven insane (at least by Cyclan standards).  Dumarest kills him anyway.  This is the first indication that the problem can now affect Cybers who are not directly connected to the gestalt.  There is also a very subtle hint given that Dumarest may have another dose of the Affinity Twin concealed in the hilt of his knife, although he does not use it in this book.
24. Nectar of Heaven. Dumarest kills Cyber Zao and renders future Cyclan influence on Sacaweena unlikely.
25. The Terridae. Dumarest destroys a ship belonging to the Cyclan.  All hands perish with the ship, including Cyber Lin and the crew of numerous acolytes.
26. The Coming Event. Cyber Prime Elge is driven insane by analyzing mental recordings of the afflicted brains in the Central Intelligence, but not before he concludes that what is happening is not really a defect but an evolution to a higher plane of consciousness.  Dumarest kills a whole squad of mercenaries hired by the Cyclan, steals one of their ships and hoplessly cripples another, but only injures Cyber Vire.  He seems disappointed.
27. Earth Is Heaven. Cyber Prime Elge has been terminated.  Cyber Avro, the strongest candidate to replace him, insists on taking personal change of the hunt for Dumarest instead, and the second candidate, Cyber Marle, becomes Cyber Prime.  Avro simultaneously seeks Dumarest and pursues Elge’s work, and although his logic seems to be mildly compromised, he handles contact with the afflicted brains far better than Okos or Elge did.  Avro finds Dumarest, but perhaps because of the contamination Avro’s logic is a little slow.  Dumarest is able to kill a handful of acolytes and inject Avro with the Affinity Twin, placing Avro’s mind in the body of a local life form.
28. Melome. Cyber Tron tries to take Dumarest into custody but is killed by Shakira.  The “angel” whose body is the host for Cyber Avro (from Book #27, Earth Is Heaven) finally dies, and Avro (restored to control of his own body) convinces Cyber Prime Marle to let him continue the search for Dumarest (although Avro doesn’t arrive on Baatz before the end of the book).  After rapport, Avro reaches a conclusion similar to that of Elge: the contaminated brains in the Central Intelligence may not be insane, but evolving to a higher plane of consciousness. Avro has now been exposed to the contaminated brains on several occasions, has been exposed to the experimental drive on several occasions, and has lived life as a semi-intelligent, flying humanoid via the Affinity Twin.  A healthy Cyber, modified to be unable to experience any emotion at all, might find it unsettling but manageable to use the Affinity Twin on a normal, emotional human.  However, the "angel's" raw emotions, animal urges and joy of flying profoundly affect Avro.  His logic seems intact, since the reasoning he uses to persuade Marle not to terminate him passes muster with the Cyber Prime.  However, he seems to have developed intuition and a survival instinct that goes beyond a Cyber’s usual logical devotion to the master plan, and is willing to deceive his superiors to indulge it.  It’s a very interesting development, and the reader is left hoping we’ll see more of this newly multi-dimensional villain.
29. Angado. Dumarest kills Cyber Ishaq and several acolytes.  He once again confronts Cyber Avro (the first time in the series Dumarest has encountered a recurring nemesis), and again there is no clear winner.  Anomalies in rapport with central intelligence lead Cyber Avro to deduce the degradation of the gestalt mind is worsening.  Avro’s own Homochon elements are swelling, a condition that usually only occurs after a Cyber’s mind is detached from the body and connected to the central intelligence (and which will eventually prove fatal if allowed to progress inside his skull).
30. Symbol of Terra. Cyber Avro’s condition is deteriorating, and the reader isn’t sure if his disturbing visions of the central intelligence are due to his own affliction or further degeneration of the gestalt minds.
31. The Temple of Truth. Dumarest kills Cyber Clarge.  No mention is made of Avro (who is presumably dead by this time) or the deterioration of the Cylan central intelligence (which is presumably still getting worse).
32. The Return. The Cyclan briefly believe Dumarest was killed by the nuclear explosion at the Temple of Truth. Former Cyber Prime Marle has therefore been exterminated for losing the secret of the Affinity Twin. However, Ryon, the new Cyber Prime, deduces that Dumarest is still alive and sends Cyber Hugas to track him down. The Cyclan develop a synthetic organism that can house the mind of a cyber in perpetuity. This could be used to salvage minds in the Central Intelligence that are in danger of deterioration, and reduces the recovery of the Affinity Twin formula from "must-have" to a "nice-to-have", cheapening Dumarest's insurance policy quite a bit. Dumarest kills Tryne, the prototype of the synthetic organism, and destroys one of the Cyclan's most advanced ships which is lost with all hands.
33. Child of Earth. Dumarest discovers the reason Earth is proscribed and kept secret by the Cyclan: native Terrans are the only compatible hosts for growing Homochon elements, a key technology enabling their quest for galactic domination. In the process he kills Shandaha, one of the Cyclan's caretakers on Earth.