Some may find this tale familiar as I have completely rewritten it to be... more in canon with Legend of Zelda.
Please note that the clans of Ikana are to be regarded as the Termina equivalent of mix between the Dark Interlopers and Twili from Hyrule.
Chronologically this story starts a few years before the incidents of Majora's Mask and finishes a little after them.
In the early days of Termina's history, there was a war in the Eastern Valley.
The Ikana, once a tribe of enlightened mages had divided over beliefs.
One worshipped the Golden Goddesses, wielders of the Light.
They believed they were the true Ikana and were tasked with destroying the foul Interlopers.
These Interlopers called themselves the Gomess, wielders of Darkness who worshipped the Giants.
Despite the divine intervention of the goddesses, they constructed the Stone Towers to act as a portal to the dark realm.
This land where time stood still was known to them as the Twilight Realm.
It was in this land they discovered a fifth Giant to worship as well as the accursed mask of the man-eater.
The emergence of this mask only ignited a long brewing feud as war was declared.
Neither the Ikana nor the Gomess were willing to negotiate.
They did not even realise the Stone Towers had created a gate to Termina.
They did not stop fighting, even as the parasitic demon, Bellum, invaded Termina.
One Gomess, Majora, proved to be different as she was the chosen of the Eastern Giant.
Equipped with forbidden knowledge of darkness, she joined forces with the Deku, Goron and Zora to banish Bellum.
She led them to become the chosen of the remaining Giants and to be capable of calling upon the masked shadows of each primal god.
They were victorious in their endeavours, they banished Bellum and saved Termina from a terrible fate.
Upon her return to Ikana, Majora was still faced with the same war.
Although her recent conquest had made her the target of a sinister plot by Arch Mage Zant.
Her soul was shattered as he tore out her malice to become an imp for him to control.
Donning the mask of the man-eater, the imp played along until the opportune moment.
When both the Ikana and the Gomess leaders were gathered on the battlefield.
The Imp unleashed a curse upon both clans, using that accursed mask as a catalyst.
The Ikana were mutated into the undead, doomed to be shunned by their beloved their goddesses.
The Gomess were exiled to the Twilight Realm to suffer a hellish fate at the hands of the demons that dwelled there.
In Ikana's darkest hour, Majora confronted her other self and the monster influencing her.
She played the Song of Healing and sealed away the demonic man-eater as well as her imp into its mask once more.
For reasons unknown she then plunged into the abyss of the Stone Towers, sealing the stronghold of her tribe from unwanted visitors.
The mask of the man-eater gained a new name that day, Majora's Mask.
However, not all mages perished that terrible day.
Majora had proved that the world beyond the kingdom of Ikana was more welcoming.
So Arch Mage Midna led her followers away from the valley and into Termina.
Yet time has passed since this ancient act and the blood of the Gomess has watered down to a handful of survivors.