So, we've all seen the original movie, yes? Now that G2 has been released, many things have been changed about the overall storyline, small details that influence the overall outcome. Take the Mask of Light storyline for example. Now that we have a new Makuta, who is looking for the Mask of Ultimate Power, this means he does not have the Mask of Shadows like Teridax. This means that the Mask of Light either will not show up or will be accompanied by a Mask of Shadows.
My theory is that the Mask of Ultimate Power only has the powers of the current toa, but leave of the elements of the expanded universe. This means that We might get other elements playing in and Makuta trying to add these powers to the Mask of Ultimate Power. It'll probably start with a villager (Takua) finding an old mask with ancient runes that the village leader (Protector) cannot read. He is instructed to take the mask to Akimu, the Mask Maker, who would be able to decipher the runes and shed light (pun not intended) on the mask.
Makuta would hear word of the mask and know that it is very powerful, and will send his forces after the villager. The toa will be tasked with protecting him, and he quickly befriends them. After getting to Akimu, he tells the company that the runes claim that the mask if the Mask of Light, but that neither he nor his brother forged it. It is then that Makuta or his forces attack the forge, and in the battle, the villager puts on the mask and becomes a toa.
What would be nice, and interesting to the story, is if the Mask of Light can also change its color like the light spectrum, and each color is an element, so they are together, but not one. This would make him the most powerful toa, and greatest threat to Makuta.
If a Mask of Shadows came with it, it would do the reverse effect, cancelling out the Mask of Lights powers, or changing to be the opposite element or power to whatever the Mask of Light is. The wearer would become Makuta's pawn or henchman, and maybe at some point the toas of Light and Shadows fuse like they did in the movie, or create a toa of Twilight like in the books.
Tell me what you think and any other ideas you guys have. This theory has no weight to it, I was just thinking about it and it sort of spilled out.