Massive AU, where what are the Matoran Universe inhabitants in prime canon are an experiment by the Great Beings to see if they can create sapient artificial life, placed on a huge artificially created archipelago in the middle of the Great Sea and left in the care of an overseer spirit named Mata Nui.

Six thousand years later the Core War is raging on the mainland, the Makuta have become deeply discontent with their role as guards against the inhabitants of the islands leaving, and a splinter group lead by one Makuta Teridax has riled up the Zyglak and sabotaged the functionality of the Great Spirit, weakening the deadly barrier storms to something almost plausibly passable.

Setting bible explaining 1. Bionicle stuff in general 2. this AU in specific is in progress.