We think there is a Kingdom of Haria (more on that in a sec), but we know there is a lord of the angels, and we know there is Oric who rules the Siblings, but we don't know about any "owner" of the Warrens.
What if, instead of a spaceship or something, the Warrens is essentially the entire universe? Sometimes, it spits someone into the top level with a soul and some memories. The only "proof" we have of Haria is a mention of it in Ciro's intro and another in Al's flashback...but we know that Ciro's memory before the Warrens is almost nonexistent, and we have little reason to think Al remembers much from before the Warrens. We don't know if Cherish remembers anything. There's an old philosophical concept, known as omphalos ("navel," since an early application was asking if Adam had a belly button, which was apparently an important theological concern), which basically points out that we don't know if the universe and ourselves have a past or if we were just created as remembering one a little bit ago. Now, in the real world, there's enough evidence for the past that this idea is horribly unscientific, but in the Warrens...well, the very patchiness and uncertainty of the evidence helps suggest that it might be fake.
Now, onto the in-Warrens people who could be considered "owners" of the Warrens. The leader of the Angels doesn't seem to participate in the affairs of the Warrens at large much, either directly or indirectly; I don't think he controls much except the Angels, who keep themselves aloof from the rest of the Warrens. Oric? He might, but--especially given the "Recreate the Prison" quote--I suspect that his history is a bit different...
Once, another person entered the Warrens. He fought through a number of individuals, reaching their leader. The leader was killed by the invader and the allies he had found along the way. But he realized that, having done this, he has nothing left to do. More people enter, trying to kill him; using his silver tongue, some are converted to his side, while others are killed. Perhaps one is given to the care of the Angels or else enchanted, so she can take a different form as a "speed bump" to the next invader. Some of the invaders come and settle down in a village rather than go adventuring, but the adventurelust is strong in them, and when the new invader makes himself a target, he manages to recruit them with relative ease. Oric calls himself the King of the Warrens, perhaps, but what does he rule? A handful of people who swore allegiance to him rather than be killed and a couple hordes of deadly Illborn. The Angels and Underside are more or less free from his control...and the Angels probably don't think much of this King of the Underside.
What are the cycles, then? One person enters the Warrens, and goes down until he gets killed, recruited, or retired in the Underside. And life goes on, Oric waits for the next fool to enter his prison.
Are you sure? Do you by any chance have a vote tally? I seem to recall a pretty good amount of support for that.