Both Light & Dark bending are types that multiple people have came up with ideas and concepts for, I'm just putting my concept down for you lovely people to read. Please understand that I've gotten a lot of inspiration from Skelton's in the closet: A Guide to Shadow Bending. He and his friend have came up with a wonderful concept to these elements from which I draw some ideas from. Please go read his work, it's phenomenal. I'd appreciate your guy's review, but please understand that these are my ideas and I made them, so please don't harass me. Anyways, on with the flowing imagination of Light and Dark Bending… enjoy!
Light and Dark Bending
History:
Both the Light and Dark elements are lost, in other words, extinct. Long ago, benders of both elements were very prominent but secluded from the rest of the world. That all changed when the Dark benders believed that they were more powerful than the Light benders, so they declared war to prove their strength against the Light benders. The war was called 'The Great Opposition' by its inhabitants and soldiers. 'The Great Opposition' started 10 years before the disappearance of Avatar Roku, and lasted for 50 years. Being secluded made this war secretive and the other elements were ignorant of its existence. Both types of benders were never seen again after the war, the other elements believed that Light and Dark benders were wiped from existence in which they'd be right, except for one.
The last Light and Dark bender, was an Avatar created specifically for these two elements. This Avatar was called the Yin Yang Avatar, one who utilized both the Light and the Dark. Yin Yang Avatar was given such generous power through a thought to be long lost Lion Turtle of Light and Dark from which the Light and Dark benders lived upon its back. The Yin Yang Avatar was created as both a mediator and teacher of the bending arts and style of Light and Dark.
The Avatar used to be able to bend Light and Dark but after the war and the benders were thought to be extinct, there was no-one to teach the Avatar these bending techniques.
The Art of Light and Dark Bending:
Light:
The moves of a Light Bender are a mixture of a Air Bender's swift evasion and speed to conjure the Light, and the forceful moves and stance to throw/strike with the Light.
Dark:
The moves of a Dark Bender are a mixture of a Water Bender's tentative flowing movements to grasp the darkness and maneuver it, then uses the hard force and strike of a Fire Bender to throw/strike with the Darkness.
Subtypes:
Just like the other elements, Light and Dark have subtypes as well.
Light:
Light Walking - To be able to use this subtype, the sun has to be out, and only benders who are absolute masters of the Light may learn this subtype. Light Walking looks like the Bender is just walking on thin air at first glance, but if you pay better attention, the Bender is walking on solidified Light, of which the Bender can traverse the skies on. The Bender can do this by focusing the Light under his feet and hardening it, allowing the Bender to traverse it, but only the Bender can traverse this solidified light. Also, the light is only underneath the Bender's feet, both having their own platforms.
Soothing Light(Healing) - This subtype is uncommon, usually healers were thought to only have this ability, but that changed during 'The Great Opposition' when healers were greatly needed and everybody needed healing. Soothing Light just takes light particles and uses them to rebuild body tissue, and on a lower scale is to ease physical pain. Doing this looks like a ray of light is pointed at the affected area through the Bender's hands. On a much bigger scale, like a broken bone, the Bender will bend a huge ray of light from the sun and shine it on the broken tissue and bone, but requires much more focus and practice.
Light's Judgment(White Lightning) - Light's Judgment, more commonly known as White Lightning, requires great focus and practice, if one should neglect respect for the Light while trying to bend this subtype will result in serious injury or death. White Lightning bending is very similar to regular Lightning bending, but instead of having peace of mind, the Bender must believe that they're doing absolute justice. White Lightning looks very similar to lightning but with a yellowish-white coloration. Also, White Lightning does not go through the target and branch off to multiple people, nor is it conductive. When White Lightning hits the target, it can cause significant damage and pain, what it does is overloads the targets energy, past their capacity, causing them to feel pain from the overwhelming energy. White Lightning can kill the target, but as it overloads the targets energy, it takes immense energy and control from the Bender to perform, so it usually isn't held out for long.
Light's Warrior - This is the most common subtype for Light, and Soothing Light is right after it because these two subtypes are very similar. Light's Warrior is when the Bender absorbs light particles and let it attach to their muscles, allowing them to have immense strength, depending on how much Light they've absorbed. The Bender calls for a ray of sunlight to beam upon them, and absorbing that Light. The Bender cannot have this effect permanently because the Light will burn and destroy their muscles after a couple of hours to a day, depending on the Bender's will power.
Dark:
Shadow's Evanesce(Fader/Walker) - This subtype is extremely difficult, both in practice and art. Shadow's Evanesce, also known as a Fader, or Shadow Walker, is when the Bender literally walk in the shadows or darkness making them invisible. Performing this is much easier during the night when much more darkness is available to traverse. The Bender is required to have great focus on darkness itself and then combining their body into the darkness. This can be done by 'falling' into their shadow or someone's/something's shadow. During the day, the Bender will have to constantly jump from shadow to shadow.
Shadow's Embezzlement(Thief) - One of the more common subtypes of Dark bending, Shadow's Embezzlement is where the Bender uses the darkness to steal/sap ones energy, healing themselves. But can also steal another's injuries if they please, by forming the shadow around another's injury and sapping it, the injury will transfer from target to Bender. This is sort of like healing, but in a more sinister way of which they actually take instead of give. This is the second most common, after Shadow's Evanesce.
Dark Torment - This subtype is very powerful, the Bender requires great focus and resilience when bending this subtype. Dark Torment is where the Bender 'bends' the target's nightmares and awful emotions, causing them to suffer greatly through themselves feeling constant pain of which they're trying to get out of their nightmare and using up energy. This subtype is very risky, if the Bender does not focus, they could get lost in their own nightmares and cause themselves to sap out their own energy.
Dark Dimension - A seriously tough subtype to master, if not the toughest. The Bender opens up a fissure to the Dark Dimension of which is a mirror of the actual world. The force within itself to actually find and open the fissure is nothing short of strenuous, then must be able to withstand the Dark corrupting the energies of the Bender, and calculate where to exit the Dark Dimension. Most would see this as teleportation, of which it is not, it's Shadow Walking on the grandest of scales.
Extras:
Light:
Light Benders are much more powerful during the day, when the sun is providing an immense amount of Light for them to use. But, even though they're weaker during the night, the can still bend the light of the moon, but not on such a grand scale compared during the day. Light Benders can also grab the glow of fire, but it's much weaker compared to the sun's and moon's light. Light Benders are at their strongest during the Lunar Eclipse, and weakest during the Solar Eclipse. Light Benders also have particularly well eyesight of which they can see a hundred yards away, and also look directly into any source of light and not get blinded, including the sun.
Dark:
Dark Benders are almost completely opposite of Light Benders, they are much more powerful during the night when there's more darkness that looms. Dark Benders can utilize any shadow or darkness, they can even use the shadow of the element of the targets bending. Example; if an Earth Bender threw a boulder at a Dark Bender, the Dark Bender can use the shadow of the boulder that is obstructing light, and 'nullify' or block/destroy the boulder before it even gets close to the Dark Bender. Or, if the Dark Bender wanted to get savvy, he could stretch the shadow over the boulder and take control of it, and they could do the same to humans, they call it, "puppeteering". Dark Benders are at their strongest during a Solar Eclipse, and weakest during a Lunar Eclipse. Dark Bender typically don't have the best eyesight because of where they live, so the rely on the opponent's shadow to interpret and even predict their next move, somewhat similar to Toph's seismic sense.
The Yin Yang State:
The Yin Yang Avatar also has a state very similar, both are activated in a state of emergency, both are very powerful, and both are controlled by their past selves. The difference is that the Avatar was able to use all the elements, including Light and Dark. The Yin Yang Avatar is limited to only Light and Dark bending, and a bit more effects happen on the person (we'll get more into that later).
Types of Moves to Create Weapons:
Both types of benders use certain moves to take the Light or Dark and solidify them, creating weapons to land hard blows on their opponents.
Light:
Light Sword - Bending the light in front of the Bender and swiftly jutting their hand straight out creates the weapon.
Light Shield - Bending the light above the Bender by "grabbing" the Light and pulling it down in front of the Bender.
Light Spear - Bending the light off the ground through the hands and gently lifting them off the ground straight up, creating the weapon.
Light Hammer - (A bit more difficult to master) First, the Bender must create a Light Spear, then bend the Light atop the spear, flattening and expanding it, giving it width, then solidifying the top, creating the mallet, then the Light Hammer is created. Only the most masterful can perform this well and perfecting it.
Dark:
Dark Sword - Bending the bender's shadow from whatever position it's in. Swiftly grasping the shadow, solidifying it, then the Dark Sword is created.
Dark Shield - Bending the shadow of the Bender by kneeling in it, putting a fist on the ground, grasping the shadow, then pulling up, the shield is created.
Dark Bow - Bending the Bender's shadow by 'grabbing a piece' of it, and forming it into the shape of a bow, and solidify it. To use shadow arrows, the Bender reaches behind themselves as if they were grabbing an arrow from a quiver, instead they grab shadow and solidify it into an arrow.
Dark Axe - (Bit more difficult to master) Pretty much the Light Hammer's equal, as far as skill and mastery goes. The Bender grabs the shadow in a similar fashion as the Dark Sword, in fact, they first have to make the Dark sword, then reform it's blade before solidifying it. Only the masterful can perfectly perform this type of weapon.
Tattoos:
Tattoos help control the chi and energy output of these elements. Without these tattoos, the Bender will die, without the regulation of chi, it would take immense energy to regulate the element bending. Using such immense energy, the Bender would be weak and sap the rest of their energy just to survive, causing them to die. No two Bender's have the same exact tattoo, but they all follow the same template/route.
Light:
The Light have tattoos only on the left side of their bodies, they have a yellowish glowing tint of twisting ribbon like tattoos that follow from their left foot, up the leg, up to the back which has the Yang side of the Yin Yang only. From their, yellow ribbons branch to the left arm, and can follow up around the up the neck and around the left ear and left side of the face, to the forehead which would have a miniature Yang, but that's for more powerful benders.
Dark:
The Dark tattoos look more like black glowing thorny vines or lightning that are only present on the right side of the body. The tattoos follow from the right foot, up the leg, to the back which only has the Yin side of the Yin Yang. From there, branches to the right arm, and just like the Light Bender's, the tattoos can go up the neck and around the right ear, to the right side of the face, up to the forehead and into a miniature Yin sign, but that's only for more powerful Dark Benders.
Yin Yang Avatar:
The Yin Yang Avatar utilizes both elements therefore, they have both tattoos, but instead of having only half of the Yin Yang on the back, they have the full. Also, they have the miniature Yin Yang on their forehead. In opposition to Light and Dark Benders, where their tattoos are always present, no matter what they're doing, but when they're bending, their tattoos pulse with energy. The Yin Yang Avatar doesn't have their tattoos always present, except for the complete Yin Yang on their back, their tattoos are only visible when they're bending the Light or Dark. If they're bending only the Light, then only the Light tattoos will appear and the Yang side will glow on their back, same thing with Dark but only for the dark tattoos and Yin glow. Now when they're simultaneously bending both Light and Dark at the same time, that is when they go into the Yin Yang state. All of their tattoos glow according to their sides, the complete Yin Yang on their back will glow and their eyes will glow. The left eye will glow a heavenly yellow while the right eye glows a satanic dark purple.
Place of Residence:
Most people didn't and don't know where the Light and Dark Benders lived, they believed that the Light Benders came from an island near the Fire Nation, while the Dark Benders were thought to be derived from Southern Water Tribe area. Both of these theories are wrong, both Benders lived on the back of the Yin Yang Lion Turtle of which the other elements were completely ignorant of. Top view of the Yin Yang Lion Turtle looks like a Yin Yang symbol. The Light Benders lived on the Yang side of the Lion Turtle's back which was very bright, open, prairie like. The Dark Benders lived on the Yin side of the Lion Turtle's back which was very dark, secluded, and filled with forest. The Yang side's Capital was called 'Sunalia', which was very beautiful and artistic, with the main building colors being light and glossy. The Yin side's capital was 'Umbrathorn', which was very dark, medieval style with the buildings being made of dark stone or wood. In the very middle of the Lion Turtle's back was a hole, a well if you will, this well was filled dark and light fluids of which never mixed but did coincide together. This well was called the 'Font of Transcendence', and the liquid actually the Lion Turtle's blood of which any first two man or creature born on the Lion Turtle was derived from it's blood. During 'The Great Opposition', the blood of the Lion Turtle in the 'Font of Transcendence' would lower and lower as the war went on, until the blood was so low, that the Lion Turtle could barely survived and which he made the Yin Yang Avatar to mediate the fight and protect him, but by the time the Yin Yang Avatar was created, the Light and Dark Benders killed each other off.
Government:
Both sides had a very different view on politics and power, the Light side believed in a Constitutional Monarchy and believed in unified people. The Dark side believed in Tribal Anocracy, having 5 tribes who would compete for political power, usually would come to 'Umbrathorn' in 'Umbraka', the center-most territory, for meeting among the tribe leaders. Very near the beginning of the war, the Dark side switched to houses of different powers of which the tribes represented what they're best at. 'Umbraka' became the House of Unity, 'Maratok', what used to be the southwest tribe, 'Marnata', became the House of Military. The southeast tribe, 'Reskinik', became 'Reksi', the House of Resource. 'Intulek', still keeping its name, what was the northeast tribe, became the House of Strategies. The northwest tribe, 'Anwaro', also keeping their name, became the House of Exile. The House of Unity overseen the loyalty of the other Houses, and has the most power upon the others to insure their loyalty. The House of Military strictly follows suit of war, combat and war strategies, no power over others except insuring protection. The House of Resource provided all resources to the other houses from which their land was the best for farming and had good mining resources, they had the third most power, ensuring everyone's survival. The House of Strategies focused on policy, they're legislative and have good ideas on how to ensure sovereignty among the people and ensure full productiveness of the substantial 4 Houses, the second most powerful House. Now, the House of Exile is exactly that, a congregation of exiles or anarchists, the poor, sick, and alien were forcefully sent here to die, had no power among any of the Houses.
Geography:
The Yin side is the northern half of the Lion Turtle's back, while the Yang side is the southern half. The Lion Turtle's back was more of a bowl, there were mountains all around the edge of his back except for an opening on his right side which allowed people to come in(if they found it without dying) and go out. Last major geographical elements is the 'Photosnia' waterfall in the Yin side of which is the white area, which water's were a bright white that tasted very sweet, and flowed into 'Photosnack River', from there into the 'Font of Transcendence'. From the font and into the Yang side, the water turned to murky purplish-black, and had a bitter taste, this flowed into the 'Noireck River' of which flowed into 'Noirecksis Lake' the black area in the Yang side.
Light:
The Light side had a very harmonious feel to it, very much open and bright, prairie and farm lands surrounding 'Sunalia', trees in open areas like the Sahara, no trees congregated together. The only forest Yang side has is 'The Division', this forest is what surrounds the 'Font of Transcendence' and divides the Yin and Yang from each other. 'Sunalia' is build in the most southern west corner of the Light side, it's the only city that the Yang side has, but it's massive and is more like a kingdom. 'Sunalia' was built all along the southern west mountain wall, and had a huge white stone wall with a gigantic arch in the middle, This is the entrance to 'Sunalia'. The castle of 'Sunalia', or 'Castle Photos', is a beautiful castle built into the side of the mountain wall, the castle is a white and had a huge staircases on both sides of a gigantic stone overhang that people must climb to reach the entrance of the castle. Which 'Castle Photos' looked like a giant, white cathedral, having an immense center tower above the grand doors, and sported a beautiful stained glass of the shining sun, this stained glass was large enough to see at the very entrance of 'Sunalia', all the way across the castle. All the buildings had beautiful, shimmering architecture, and they were only colored white, light yellow, or sky blue. They all have smooth, and seemingly edge less architecture, where every conjunction or wall flowed into each other.
Dark:
The Yin side was very gloomy and dark, there's only types of habitats, swamp and forest, forest was the most overwhelming, going from 'The Division', and spreading across all territories except for 'Anwaro' of which was all swamp. 'Umbrathorn' is in the most center in the Yin side in the center territory, 'Umbraka'. 'Umbrathorn' had a very medieval style of architecture, and gothic feel. The 'Untook Manor' is the residence of the 'Umbraka's' leader, the building was in the center of 'Umbrathorn', which was surrounded by forest, secluded from the other territories. 'Untook Manor' was made of dark stone and wood, and was very eccentric and very eerie feel, and was massive and intimidating to look at. The other territories, except 'Anwaro', followed suit in their towns, with the leader's house being in the middle, but none were bigger than 'Untook Manor'.