If Light were a bendable element in the Avatar world, what would its potential nation and bending style be like?
"The sixth pool of energy is the Light chakra, located in the center of the forehead. It deals with insight and is blocked by illusion. The greatest illusion of this world is the illusion of separation. Things you think are separate and different are actually one and the same. We are all one people, but we live as if divided."
—Guru Pathik, from The Guru episode
Design: I theorize them to be a dark-skinned majority with white hair and unique type of irises.
Culture: they are a small nation overall, maybe even less than the Airbenders--not as numbered as Fire Nation and Earth Kingdom. Ideally, they focus on enlightenment (not entitlement), maybe even more so than the Air Nomads, but they are more in touch with the world for beating the illusion of separation; the greatest illusion of all. The colors of their costume are white and sky blue.
However, if they are in touch with the world, then why they are a small nation? Probably, because their biological element (light) is less likely to be inherited through generations of merging into larger nations, resulting for it to reappear as recessive trait e.g Combusting bending (firebending released from the third eye).
That, if they were genocided by the Fire Nation or any other groups.
Exclusive Light-bending techniques:
Glowing: skin and eyes glow, similar to but a lot fainter to the Avatar State, thereby making them appear as a natural lamp in the night.
Invisibility: is achieved by warping the light waves around the bender's body, rather than allowing the light waves to bounce back to eyes. [a detailed analysis of how it feasibly works]
Enhaced perception: like how there's Earthbending and Airbending senses, a lightbender is spiritual connection to their element as well. It provides them a wider, more extended vision, and simply allow them to avoid moving blindly when invisible.
Third Eye: the ability to see in faraway places. In canon, while Aang was in the middle of activating the Thought chakra, he saw a vision of Katara in danger, though that vision was arguably inaccurate because Katara appeared to not be in chains. Therefore, Aang's anxiety may have caused him to receive an inaccurate vision (illusion); hereby, the accuracy of the Third Eye depends on the detachment of the Thought chakra.
Sensory overload attack: light is a form of energy that carries a lot of information about the world, therefore a light bender could use this to attack and overwhelm an opponent's brain with information. [inspired by but second only to Satoru Gojo, of course]
Darkness: Like how Airbending could take people's breath from their lungs by warping a bubble of void around their head, a light bender could steal people's sight by not allowing light to reach their eyes in the first place, thus making them temporarily blind.
Travel or flight: This is a trickier one and probably only Avatar-level, though just like how Earthbenders travel faster by riding earth waves (while Waterbenders ride or swim in water, Airbenders fly easily with glider or even without, Firebenders fly by fire jets, etc.), light waves theoretically could be used to travel or teleport as well, albeit much faster than the others.
Anyway, Toph would absolutely destroy any Lightbender.
Inspired from "Sky: Children of Light" videogame