The End

The End is an entirely separate world from Rathnir and Eldham, similarly to the nether in this regard. There is no official term for everyone who lives here, but the most commonly used one is Endfolk. It's theorized to be many things, including an afterlife, a save haven from the cataclysm that destroyed Paxia and Jagdas, and a place far beneath the void that it's horrors couldn't reach. Unlike the nether however, travelling to and from the end is only possible through an end portal, or powerful teleportation abilities that higher beings and endermen have. The former of which being almost non-existent in Rathnir and Eldham.

Geography
The End consists of numerous floating islands that are hundreds of meters long, and made out of the same material that The Boulder is made of. These islands aren't completely barren though, as life vastly different from that on Rathnir and Eldham, such as chorus plants, live on the islands and the space between them. These floating islands cluster together in rings, which are comparable to continents. In the space in between these rings is a kilometer long sea of nothingness. At the center of all of these rings is a lone island, called the Central Island.

History
In the most widely used calander, called the Zenithian Calender, time is divided into 3 "Free" ages, and 2 "Chained" ages. During the First Chained Age, the end was ruled by a nation called the First Regime by scholars, run by a powerful being from the void, who was also called Void. Allegedly, this being was also the one who destroyed Jagdas and Paxia in order to create more Endermen, but this is unconfirmed. In order to prevent the Endfolk from rebelling, Void stripped them of their free will, consequently erasing much of End culture and history from the First Free Age. Fortunately, another void being, called Zenith, disabled Void's spell in what's called the Great Liberation, marking the beginning of the Second Free Age. This caused most the First Regime to dissolve overnight, save for a small portion of land now known as the Void Order, which remains loyal to this day. After this, the first 5 rings agreed to unite under Zenith, forming the Zenith Union However, this all changed when Entropy found the end, which she could access even while being imprisoned. She wanted it for herself. So, she amassed as many followers as she could, and made a deal with the Ender Dragon, a creature who roamed the Central Island since the first Free Age. So, in an event called the Great Schism they overthrew Zenith and cast him into the void. Afterwards, she swiftly took over the entire end once again, creating the Second Regime. and bringing about the second chained age. Luckily, this chained age would only last a few decades, ending when Athaz destroyed Entropy once and for all and unwittingly freed the entire end once more. In entropy's absence, the Ender Dragon stepped up to take her place, and was able to keep the central islands under the newly named New Entropa.

Trivia
Regimes are referred to as just "regimes" because they didn't actually have an official name besides "The End", since both Regimes simply didn't have a need for one.