Alara was whole once. But that was a millennia ago. Where once there was a plane, now there are 5: the shards.
The plane of Alara was a world rich with mana, a world in balance... until the sundering. In a cataclysm of unimaginable proportions, Alara was torn asunder into 5 separate worlds, each a refraction of the others.
The cause of this cataclysm has been lost to time. Some ancient lore of the shards suggest a being of god-like power forcibly split the shards to seize its mana. Some believe it was caused by the titanic battle between the archangel Asha and the demon Malfegor. But for most, only the dimmest cultural memories remains of a richer world that existed before their own.
Whatever the cause of the sundering, one thing is clear: The shards have become very different places in the time since the sundering. Each plane was all but severed from two of the five colors of mana. the shard of Bant, lost all of its black and red, keeping white, green, and blue.
This mana imbalance caused the shards to evolve in wildly distinct directions over the course of one thousand years. Now only hints of a common ancestor plane remain on the 5 worlds, and their environments and denizens could hardly differ more.
Naya: Life, passion, community, and the wild- these are what flourish without the influence of black or blue mana. In this lush land, life is celebrated. Instinct triumphs over machination. Here titanic predators are shown respect, while humans, elves, and catfolk called leonin seek to revere and respect nature.
Bant: Without the destructive or selfish impulses of black or red mana, Bant has become a golden utopia. Angels rule this world with benevolence and grace. Humans and the birdfolk called aven resolve their conflicts with ritualized combat. Duty and honor are the bedrock of this kingdom of light.
Esper: In this world of wind and wave, control is the guiding force. Cut off from the chaos of red and green mana, Esper has become a magocracy. Enigmatic sphinxes consul powerful wizards and seers. Everything here is observed and controlled. The forces of high magic rule supreme.
Grixis: What becomes of a world without new life? The dark wasteland of Grixis answers the question. The denizens desperately cling to the remaining lifeforce. Without the communal forces of white and green to bring life and compassion, it's every ghoul, demon, and necromancer for themselves.
Jund:In absence of white or blue mana, Jund has developed into a roilling, primordial cesspit. Dragons top the food chain at home in Junds countless volcanoes. When cards attack dragons come to help.Humans fight against the Dragons. While dragons stalk the skies, humans, goblins, and lizardfolk called viashino lie low in Jund's tar-spotted, vine-choked canyons.