Let me know what you think of this.

Years after the end of the Karda-Nui saga, the Toa Nuva were driven into insanity by Teridax who's plan had failed. In the process of said insanity, Mata-Nui was not awakened. Shortly after, Teridax reached out before dying and fixed the Nuva's minds, but corrupted them as well. Now, each rules as a king (or queen in Gali's case). Each rules their own kingdom, forged in their elements, destroying whole islands to forge their kingdoms. Metru-Nui remains, not even the Shadow Nuva foolish enough to dare try to take it in case it is destroyed.

Each of the Toa has a following, such as Tahu, almost all Ta-Matoran and fire Toa and Turaga follow him (though beings like Skakdi of fire don't and were wiped out by Tahu's army, same with the other elements respectively). Only rebels who can see through their new actions dare stand against them. Takanuva, freed from his light drain by a Klakk is now a wanderer. He did take something away from his freement however, he has a black and white sense of justice and stands against the Nuva. The Order was wiped out in battle with the Brotherhood and then blindsided by the Dark Hunters, resulting in the three organizations being destroyed, only members (except the Makuta, servants) remain, in very few numbers.

The Shadowed One, Brutaka, Helryx, Krakua and few more notable beings exist as rebels in Metru-Nui, where they know the Toa's armies won't dare strike. However, Helryx doesn't believe them unreedemable and went to see Gali. Gali was enraged and beyond talking, attacked Helryx. Helryx was slaughtered but she got a message back to Krakua before she was killed. The message had something along the lines of "They are too strong in their realms, our powers are below theirs if we fight them in their kingdoms", an ominous message. Krakua and others with him must now find a way to stop the armies from conquering more lands, by joining with the surviving members of the other tribes, like Magnetism, Iron, Plasma, etc. who the Toa slaughtered most of early on. But there's always threats like Takanuva who has grown in power tremendously, able to use the Av and Kra (Shadow Matoran) powers from Karda-Nui almost on command. The Nuva however, are waiting to claim final victory and rule Metru-Nui without a massive invasion force or destroying it in the process.

How's that sound? I'm personally just bored and nearly out of stuff to write.