On the outer fringe of the habitable zone in a damaged pocket of space-time called Hava is a half-frozen rock, named Illera, meaning 'manifestation,' by the ancient Lilitai. Around its middle is a temperate land that, although almost completely barren, is suitable for growing Terran crops, provided adequate soil is imported. The planet is not particularly geologically active, although it has an oxygen-rich atmosphere due to the few native prokaryotes. Almost the entire surface consists of mountain-ranges, small pools of metal-rich water, and intricate cavern systems; what few continental shelves the planet possessed were broken up during a second Hadean aeon caused by the formation of a black hole nearby.

Hava is the ancestral home of the Peseneyi, who inhabited the planets of another star system within it long ago; that star was consumed by the great Hava Vortex, along with its planets. This singularity is not entirely stable, and is expected to devour the rest of the worlds in the brane in one or two million years. Although no remnant of Pesenese civilization remains in Hava, the remaining rocky worlds are littered with koplazai—non-sentient cousins of the Peseneyi that feed mostly on algae and each other.

Illera has one major settlement, Koitra, which is situated directly on the equator. It was originally established by the Lilitai with the name Koisilitra (meaning "community" or "neighborhood") in 672 lilpo, but the shorter term was quickly adopted. Although Koitra was abandoned in 829 lilpo following the plague, it was repaired and re-occupied with minimal alterations in 1924 iky by the settlers of the second colony.

Illera's unique position at the fringe of a heavily-damaged brane allows it a unique set of visitors; in addition to the Lilitai, it is believed that the Rotomem most likely saw this world first on their travels in the Ksreskézaian Expanse, and that it was visited by early humans from Earth hundreds of thousands of years ago, who left behind cellular residue that eventually immortalized into the cancerous pathogen responsible for the aforementioned plague. It is also the only reliable way to access Makta, a similar planet in a partially disconnected brane that has a subterranean colony of self-ruling Pesenese robots.

The second colony on Illera gradually grew from a village of five hundred to a metropolis of a few hundred thousand, resulting in several satellite cities around Koitra proper. For the first three centuries of its existence, Illera was beheld by the Lilitai primarily as a religious retreat, as many of the temples built by the students of Sarthía still stood, a testament to a millennium of independence and self-determination away from the nurturing (but sometimes constricting) assistance of the much more numerous Lyrisclensiae. By the end of the Iunen calendar on Thet, Illera not only represented the largest population of Lilitai, but had become moderately xenophobic, discouraging visits from (and denying residency to) outsiders.

Illera was initially ruled by the same Council of Elders as the Lilitai on Thet, but over time they fostered their own circle of aristocratic bloodlines, including a monarch bloodline, called Illera. The best known of these is Venakoa Illera, who was apprenticed by Locussa Didacta in an attempt to mend the rift between the two peoples.

Following the ascent of the Gripsení Mitraje in Thet and the subsequent expulsion of the Lilitai in the 51st century tgc, Illera received many new immigrants from Thet, mostly Lilitai who had spent their entire lives knowing few other members of their own species and were accustomed to the archipelago's extremely multicultural environment. By the time the Gryphon government collapsed in 5811, the Thessian Lilitai had left an indeliable mark on Illera's cultural fabric, quelling the ancient xenophobias that had long ago been eliminated on Thet, and, indeed, more returned to the archipelago than had originally fled from it.