Have you ever known someone who was just this big bright light and it was almost scary how much light they could give you in one moment like you couldn’t handle it because you would drown or burn up or dissolve and so you end up pushing them away?

Obligatory theory that everyone was in the Red Lotus at some point or another and set out to exact the mission in their own ways for their own reasons.

Amon might have found them during the years missing after that snow storm. He could have gotten the idea to utilize his abilities (that, to the Red Lotus, are seen as a gift to be used for the greater purpose) to draw out the Avatar and reform the natural order of chaos. Additionally, Noatak could have been appreciative that his blood-bending would be seen as a good thing, instead of how he had always seen it: as a curse bestowed upon him by his father.

And of course we already know Unalaq defected and pursued personal ambitions to rule the world and forcefully restore the world’s spirituality.

Bryke had said Korra would face different individual enemies per season… but perhaps they are actually all connected.