The Prologue.it kinda just explains what happened before the events of Kardas Quest.This story is also a tie in with A Story Retold.
About this creation
There were 7 Great Weapons that had Ultimate power over the elements.The elements were the six basic elements and light.Only those of pure heart and a good cause could use them as revenge and evil Destroys all.The weapons were Protected by a force that can destroy any evil that touches it and anyone with revenge in their heart could not touch them.They were Crafted by a One of the Three Toa that made the Universe,Mato the creator.Their powers combined can Destroy Great Evil.
However they were used once then they vanished,never to be found and soon to be forgotten
The Ignika brought life to all but was soon forgotten
It then left the Matorans and hid it's self,waiting for when it was need
Vahi knew he was alone as the Mask of Creation was gone,lost since Artakha left to be with the Great beings.
He then left too, fearing for himself, floating through time
Then Makuta Tyzel saw his chance and Darkness took over
All but one star remains.If the Universe is to survive,the Weapons are need to battle the shadows and return the light.
well it explains what happened before the story.if you don't understand you'll piece it together.