History seems bound on repeating itself. Eventually, the more observant of Our Heroes will notice that the Azytwaznt Steampunk Era is disturbingly like a foreshadowing of the decadent Antediluvian Epoch. (Work to create more parallels between the two, and plant clues!)
Previous cycles have not all be human-dominated. There were Saurian (dinosaur), Devonian, and Precambrian (radially symmetric pre-chordate invertebrate) cycles. Studied carefully, patterns may emerge. Disturbing patterns, suggesting SOMETHING is manipulating these cycles, SOMETHING with an infinitely long plan and the patience to experiment again and again. What is ITS goal? How close are we of the current Cycle to achieving it? If we succeed, what is the stage AFTER the Cycles of History? Are the Cthulhuseque horrors parts of the Cycles, invaders from other Cycles of other star systems - or other planes of existence - or are some of them outside the Cycles? WHAT are the ultimate puppet-masters? How do they manipulate us?
Braided Time
In addition to the main time stream I have concentrated on there are innumerable - possibly infinite - other time streams. The ease of "slipping" between them varies by who and when you are.
Exploring the Past
Time travel to the past would set up irreconcilable paradoxes save that the act of re-entering the time-stream creates fission. The very arrival of Our Heroes (or others) in the past starts a branch time stream. One can also travel from one time-stream to another, but this also sets of a new stream.
Class, Race, and Gender
Azyntwaznt is based on the Victorian mindset. Their wildest speculations are taken as fact and extrapolated. This includes concepts of class, race, and gender that are quite foreign to most modern folk. Some believed that there were "scientific" reasons for differences in ability and station for different classes, races, and the genders. As a tempering of the extreme belief in inherent inferiority, I have decided that the Victorian science of phrenology, or cranium measurements, and physonometry, or facial measurements, trump race and gender. Thus, there can be "noble savages" and ancient high civilizations in sub-Saharan Africa, there are still physical reasons why the "laboring classes" of Europe are best left to their low stations. Gender and jobs
Likewise, most women are simply not psychically suited to the pursuit of masculine activities. Exceptions, however, are perfectly acceptable; any decent phrenologist will be able to point out the high brow and strong nose of the unusual woman who demonstrates sufficient determination to become a doctor, explorer, or even huntress. She will be considered the exception that proves the rule. Race and Civilization
There are held to be particular racial and sub-racial characteristics. Those who are "pure" may be of elevated potential, while the low, misengendered, mongrels are incapable of being raised above their natural station. Of course, the drive for purity can bring the danger inbreeding.
Class
The classes are "obviously" subtle divisions of the same nature as the greater racial divisions. How persons of classes within the races compare across races is a matter for debate. Clearly a highborn West Indian prince is naturally superior to an English peasant - unless the princely families are overly inbred or hide secret interbreeding.
Artificial differentation
Given the Victorian lines of thought, it should be possible to purposefully breed both servile classes and ruling classes, as distinct as different breeds of dog.
MAJIC vs. MENTAL SCIENCES
True Majic, the Dark Arts, are forbidden for good reasons. They are an extremely dangerous perversion of the super-natural laws which bind the universe together. Dark Majic is the art of tapping into power from other dimensions, weird and alien. To do so requires the practitioner to twist his or her mind in manners so perverse that he or she is able, however feebly, to grasp some inkling of the workings of these other dimensions. Such foolish folk are soon driven mad by these insights.
The real danger lies with Those Others which dwell Beyond. When they scent the scratchings upon the walls of their timeless cells, they answer. Inevitable, they send their horrific shadows of their dreams to follow the energies flowing from their dimensions to ours. Such shadows can take form and substance here when a gate has been opened. Cthulhu's cousins are numberless, insatiable, infinitely intelligent, and patient as only the timeless can be.
The Mental Sciences are the crowning glory of many a civilization. They work by using Tuned crystal to focus and amplify the faint brainwaves all mental activity produces. Those versed in the Mental Sciences can master their brainwaves sufficiently that they can influence other, greater energies, as the faint but controlling factor.
Crystals may be like large gems. Some flat crystals are formed into mirrors, to aid in the mental exercises. Gems set into artifacts are generally used as a personal focus, and may be strongly tuned to the individual. Many are portable.
Structures, such as single stelae, an entire palace, or just the pillars of such a palace, may be tuned. Note that solid stone functions as a crystal, even though it can resemble any fine-grained stone, as it is a sort of reconstituted stone made from sand. So, the crystalline nature of the structure may not be obvious.
Vast networks of tuned crystal may be made by tuning salt, quarts, or other naturally crystalline geologic strata. In this manner, whole regions may be made friendly to the exercise of the Mental Sciences. In decadent times, these networks may break down, flickering unpredictably and eventually failing. When this happens an increasing reliance upon "talisman" artifacts is seen, even when the real working of the crystals or gems is no longer understood. This can bring on dangerous times, as the desperate may turn from the Mental Sciences they no longer understand to the eldritch Dark Arts they should not.
Lunar cycles may not be irrelevant to the workings of the Mental Sciences upon a given world. Even the faint natural tuning of scattered crystals of a moon can be powerful when one stand below their mass. Many an ancient civilization has increased this by artificially tuning the natural crystals of their moon or moons.
CHRONOLOGY
This is the meta-history against which, or the remains of which, the dramas are played out.
Interstellar civilizations have colonized our Solar System, long before humans were created. Repeatedly.
Alien Races who Conquered Earth in the Distant Past, Seeding Her with their Star-Spawned Ecologies
The Coelenterates
The Echinoderms
The Mollusks (or before the Echinoderms?)
The Crustacea
The Arachnids
(There should be a botanical civilization in there as well.)
Each rose to dominate a vast, inter galactic civilization for a number of millennia, and each has left is mark upon our system. Most obvious are the descendants of ancestors of the various life forms they brought to our seed our little star system from their own alien native ecologies. They brought their biota here much as we, perhaps, will one day bring our livestock, crops useful and ornamental, pets, and parasites to the stars with us. Naturally, these have evolved over the billions of years they have been here, loose upon the various planets and moons of our system.
Being masters of medical super-science, these former master races naturally played with, for practical and aesthetic reasons, splicing genes from one group to another. Thus, it should not surprise us that some hybrids proved viable; hybrids are descendant, not ancestral, links between the lineages.
The advent of each of these interstellar civilizations upon our system is seen in the fossil record, when a "group with few previous fossils seems to suddenly appear, to speciate in wild profusion and diversity, and then, calmer, take its place as yet another major group of Earth's creatures or plants."
The Ophidian Period
The Ophidians were Earth's first native civilization. See HP Lovecraft for details.
The Saurian Period
The Sauriens were Earth's second native civilization. Their time on Earth ended when their Earth went to war with Luna. Luna responded by firing gigantic volcanoes, up to a mile wide, as cannon at the Earth. The volcanic system ran out of control, and erupted all over Luna. Today one can still see the profusion of extinct volcanic craters and the craters where their ejecta fell back upon the surface of the moon. (Extinct - or just tamed?) Luna was the more injured of our twin spheres, but it was enough to wipe out the Saurians - almost. Only a cryptic remnant has persevered. (OK, so WHY did they feel they had to stay hidden all this time?)
(WHO CREATED HUMANS?)
Other Earths
Fallen Worlds, Dark Worlds, Lost Worlds
These are worlds that now lie under the rule of aliens. Some have been enslaved by unnatural Cthulhuesque powers, weird and occult. Others have been colonized by aliens more mundane, whether from Mars or from terrestrial worlds circling distant stars. A few were not lost but rather were never gained; here Dinosaurs may yet rule. Some worlds may seem modeled after the mythologies and legends of "primitive" peoples, while actually the truth is the diametric opposite; it is glimpses of such worlds that inspired the ancient legends. Our Heroes may also discover that some worlds are closer to the Dreamlands than others…
It is likely that, at some point in their adventures, Our Heroes will fail to save a world. Then, they may witness its transformation into such a place. Or, some one may come from such a world seeking their help. Or Our Heroes' world may be in danger of invasion from such a world; it's not only the good guys who are discovering how to slip from one time-stream to another!
Other Solar Systems
Azytwaznt tells of many interstellar empires. There are billions of stars worth adventuring to.