Level Up (A5E) ENterplanetary DimENsions: Xenial Xyclione

Once more ENterplanetary DimENsions is headed for a strange realm, this time to a place where nature runs as rampant as the incredible monsters that dwell within it: Xenial Xyclione!


Illustration by Joyce Maureira

The plane of Xyclione is ever moving forward yet in this place nature’s cycle has been somehow led astray—species proliferate and die out in years instead of eons, and creatures not native to this mutable dimension are transformed by it even faster. How Xyclione came to its state of constant change is an enigma that some are still trying to sort out (though few have any chance of success other than the longest-lived sages). There are those who are starting to suspect the truth: the entire realm is not just in the shape of an ouroboros, its denizens and their progenitors and their progeny are held just as steadfast. What once was efficacious for a creature becomes a liability, it dies out, the thing that saw its ultimate demise then suffers the same fate, and after a dozen iterations or less that same old behavior or biological quirk arises anew.

Few things cannot be found in Xyclione save for caves and deserts; pressure beneath the surface is too great for passages or tunnels, and life there is too abundant and eager to leave any area barren. The peculiar nature of the world encourages flourishing environments like grasslands and forests of all kinds, as well as rivers and seas flowing into them, all teeming with astonishing flora and fauna. These creatures are sometimes carnivores and sometimes not, but all of them are ravenous eaters, growing and dying at rates faster than similar things in realms elsewhere. The flow of evolution is far too swift for civilization to take root among the native creatures of Xyclione, and no settlers yet have been able to resist the plane’s pressures to change long enough to establish little more than ruins.

Planar Traits. Xyclione has the following planar traits and the Narrator should make use of the acid, brown mold, green slime, heavy precipitation, lava, miring ground, poisonous plants, rushing liquid, webs, and yellow mold encounter elements. When it is possible to do so, noticing one of these encounter elements before it is too close to avoid requires a DC 16 Nature check.

Changing Consumption​

Nourishment is bountiful throughout Xyclione but only the brave, foolish, or truly desperate dare consume anything found there. The pollen from plants in this dimension is extremely potent, its very nature transforming and altering whatever blade of grass, leaf, or tree it comes into contact with. Although to the naked eye nothing is noticeable, the fundamental properties of a plant can change several times before it is consumed—yet its legacy does not end there. These transformed plants are eaten by various creatures, who in turn are eaten by still more, resulting in entire ecosystems thriving on the basis of a substance that promotes rapid change. Though easily sneezed away or otherwise eradicated by a creature’s natural vigor, when the pollen-touched meat or plant enters into the stomach it is an invitation to entropy.

When a creature not native to the plane consumes Supply from Xyclione it makes a Constitution saving throw or suffers an effect based on the Supply’s basic substance type (see Table: Changing Consumption). A creature can only be affected by a substance’s initial effect, secondary effect, or final effect at a time, but may be simultaneously affected by multiple Xyclonian substances. After a week has passed without consuming any Xyclonian Supply, a creature ceases to suffer from its current effect of Changing Consumption, moving from final effect to secondary effect, secondary effect to initial effect, or initial effect to none.

Table: Changing Consumption

Extreme Evolution​

A lifetime of eating the transformative substances on Xyclione rapidly accelerates the process of evolution. Creatures native to this dimension are able to eat their fill without suffering immediate effects from doing so, but everything their progeny inherits is leaps and bounds different; some offspring can each possess traits neither shares with each other or their parents. Otherwise the plane’s powerful pollen only causes transformations in those allergic to it, but these changes are not just drastic—they are instantaneous.

When a living creature is bloodied while on Xyclione it rolls 1d100, adding 1 for every time it has been bloodied since finishing a long rest. On a result of 100 or higher the creature undergoes an extreme evolution, as listed below. An extreme evolution can only be removed with a casting of greater restoration, heal, regeneration, or wish.

An aberration, beast, celestial, dragon, fey, fiend, giant, humanoid, or monstrosity that undergoes an extreme evolution rolls 1d6, randomly determining an ability score to increase by 2. In addition, its body transforms (roll 1d8 and see Table: Extreme Evolution). Finally, whenever the creature finishes a short or long rest it rolls 1d6, gaining the secondary effect of Changing Consumption until it next finishes a short or long rest.

A plant that undergoes an extreme evolution increases all of its ability scores by 2. In addition, it cannot be frightened, rattled, slowed, or stunned.

Extreme evolutions fade after a creature spends a month or longer away from Xyclione.

Native Evolutions. Aberrations, beasts, celestials, dragons, fey, fiends, giants, humanoids, monstrosities, and plants native to Xyclione automatically gain an extreme evolution. This extreme evolution is permanent.

Table: Extreme Evolution

Greenery Graves​

Choice bits from the corpse of a dead creature in Xyclione rapidly disappear to carrion eaters and eager insects before being overtaken by vehement vegetation, usually within a matter of hours or less. What remains on bones or monstrous hide congeals as it is fed by the pollen, growing into brown mold, green slime, and yellow mold. Cadavers are also a common source of troublesome pests (or voracious pests) and rot grubs.

Mighty Markers​

Past attempts to rein in the wilderness of Xyclione defiantly reach out of the earth towards the sky, great pylons of stone that rise above the trees. What is remarkable about these structures is that they resist the aggressive vegetation that overtakes all other things—and the powerful presence of each can be felt by all nearby. Though unpleasant to endure, these mighty markers are both a way to make sense of the landscape and provide an amount of safety for those in need of a place to rest. Creatures with an Intelligence of 4 or less are unwilling to go near a mighty marker unless coerced, and in general the native species of Xyclione avoid them unless chasing down prey or otherwise lured.

At the end of each minute a creature is within a mile of a mighty marker, it makes a DC 20 Charisma saving throw or it is slowed for the next minute. At the end of each of its turns, a creature repeats the saving throw, ending the effect on itself on a success. Once a creature has successfully resisted the effects of a mighty marker, it is immune to that mighty marker’s effects for the next hour.

Magical Navigation​

Observing a mighty marker while under the effects of detect magic reveals a mile-wide aura of transmutation around it, but also auras of divination magic shaped like arrows of varying length. Each arrow points to another mighty marker with a length appropriate to the distance between the two—after traveling between three mighty markers following these divination arrows, a DC 8 Intelligence check while looking at one reveals the distance it describes.

Rounded Reality​

The dimension of Xyclione is inside-out: the sky is at its center and gravity’s pull is greatest furthest away beneath the surface. When one stands on the ground on this plane they are looking inward if looking up, or outward while staring down. Consequently the only way out is by digging down, and few things are able to move earth and stone rapidly enough to do so—or survive the journey.

There’s light gravity while 50 feet or higher above the ground (or at the Narrator’s discretion, high enough up a tree or mountainside), and heavy gravity begins 50 feet beneath the surface (or at the Narrator’s discretion, deep enough in a canyon or valley).

Crushing Excavations​

Xyclione pulls hard at its dirt. Going down beneath the surface is difficult and dangerous, the risk of even pits collapsing in on themselves a certainty—what is not known is if destruction will take seconds, minutes, or hours. This normally makes burrowing creatures something of a rarity, but the rapid evolutionary cycle in which the dimension is stuck keeps it a desirable trait in at least one region of Xyclione at any given time.

Xyclione Pressure. At the end of each minute spent more than 400 feet beneath the surface of Xyclione, a creature or object must make a Strength saving throw (DC 8 + 2 per previous successful save). On a failed save, it takes 2d6 bludgeoning damage per 400 feet below the surface. Gargantuan and Titanic creatures automatically succeed on this saving throw.

Endless Sky​

Sourceless light shines down onto the surface of Xyclione at all hours. This eternal luminescence is not just a curiosity but a tesseract as well, creatures flying into it magically losing any sense of direction as feet suddenly become miles. The only way out is by falling which results in the creature reappearing in the same area it flew into the tesseract from.