Can you draw parallels to other themes and ideas to your story/lore to why your system has powers to begin with? What does it mean for a person to have powers in your setting?

I was thinking about a way to add a black flash to a magic series I had. I thought instead of just having it hit hard, it disabled your opponent.
A Scatter is technique only Gods, and Dragonborn can use (With one exception). You can do it by making the mana in your body flow into itself and focus to a point. When someone is hit by it their magic will “scatter” leaving a shattered looking mark on impact; however, the magic will return and mark fade depending on the victim’s and attacker strength.

I got inspired by a random memory about M Night Shamalan's avatar movie. Say what you will about the movie itself but their bender test used on Aang was curious. Snuff out fire, pull water into a circle, stand up a rock. Or at least that's what he did. And his reaction after stuck.

"You said I could go once I took the test."

"But you passed it, and nobody ever has, so we can't let you go."

In my world people have magic linked to their blood, and the only way to access true magic is by offering it to a god when you come of age or education. So the race that carries out the ritual tests various elements when blood is set to them and whichever one reacts is the "winner" and off you go with a mentor for practice in using it. So trickle some blood onto a fire and it'll change color or grow in size or take a certain shape...or do nothing, meaning it isn't your magic.

So what about you?

Sorry for so much writing, but it has all necessary information and limitation. It’s based off many systems such as Nen and Cursed energy, and others I’ve seen in literature. I would like help for it to improve and what to do better.

In this world, runes are used for magic, however, creating a runestone comes at the cost of a very particular and rare type of stone, named Banestone, a small pinch of an ingredient, and a proportional amount of blood. The larger and stronger the runestone, the more blood it needs. This has complications, and one rune user even suggested turning a rune user's skeleton to banestone, then putting all their blood into it, but this was swiftly realized as idiotic at the time. There are 26 runes that can be made, each requiring different ingredients and having different magical effects.

1. Asu, Ice, requires a bit of ice (Beran)
2. Beran, Fire, requires a lump of charcoal (Asu)
3. Chiro, Night, requires a bit of spider web and a drop of oil (Kimh)
4. Dendi, Door, requires a wood splinter and a copper nugget (Mesu)
5. Ettas, Thunder, requires a small copper rod (Jimak)
6. Ferot, War, requires a nugget of raw iron (Retu)
7. Gendo, Growth, requires three blades of grass (Nekon)
8. Hasu, Health, requires two drops of aloe (Xarus)
9. Izan, Earth, requires a pinch of dirt (Lona)
10. Jimak, Wind, requires a swans feather (Ettas)
11. Kimh, Day, requires a dead firefly (Chiro)
12. Lona, Water, requires a drop of water (Izan)
13. Mesu, Barrier, requires a nugget of raw gold (Dendi)
14. Nekon, Rot, requires a bit of rotten flesh (Gendo)
15. Oruma, Mirror, requires a shard of obsidian (Tolim)
16. Pevir, Rope, requires a short length of twine  (Seter)
17. Qusun, Strength, requires a length of ox tendon (Vilu)
18. Retu, Repair, requires a shard of bone (Ferrot)
19. Seter, Steed, requires a long strand of hair from a powerful stallion (Pevir)
20.  Tolim, Bell, requires a miniature silver bell (Oruma)
21. Uro, Stone, requires a bit of mica (Wes)
22. Vilu, Will, requires a splash of spinal fluid (Qusun)
23. Wes, Magnet, requires a chunk of magnetite (Uro)
24. Xarus, Disease, requires a parasitic wasp larva (Hasu)
25. Yula, Calm, requires a sprig of an olive branch (Zolic)
26. Zolic, Fury, requires an olive leaf that has curled and withered from the poison of the blossom of the nightshade plant for three days (Yula)

In addition, you may combine the power of these runes, with three at a time being the maximum recommended for keeping effects stable. For example, you may combine Ettas (Thunder) and Tolim (Bell) to create a massive blast of lightning, with bolts of electricity striking everything nearby. This effect combines the elemental effect of Ettas with the emitter/shockwave effect of Tolim to create a powerful blast of electrical might. The rune names listed at the end of a runes entry is the rune that acts as a counterpart to the other.

I understand why they simplified it or removed it but the original idea of the magic system and benders and nations and how linked everything was and how important balance actually was is quite interesting.

In a lost age…

Power is balanced among four great Nations: Water, Earth, Fire, Air. An order made up of men and women lead each nation. These masters possess the ability to manipulate their native element.

They call themselves Waterbenders, Earthbenders, Firebenders, and Airbenders. The most powerful bender in the world is the Avatar, the spirit of the planet incarnate. He alone masters all four elements and maintains world order.

Disaster Strikes… …when the current Avatar dies. Taking advantage of the opportunity, the Fire Nation’s leader launches a global war. His goal – eliminate the Water, Earth, and Air Nations so that the Fire Nation may rule for eternity.

100 Years Later, the Avatar returns… With the Fire Nation on the brink of global domination, a young girl and her brother living on the South Pole make an amazing discovery: Enclosed within an iceberg for 100 years, a 12-year old Airbender has miraculously survived. Waking up hungry for food and adventure, the boy reveals himself as the Avatar. But will this irresponsible kid accept his destiny in time to save the world?

What is the Avatar?

The Avatar is the incarnation of the Spirit of the Planet in human form. There is only one Avatar, who reincarnates himself through the centuries. Each time the Avatar dies it is reborn into the next nation.

This successive cycle mirrors the order of the seasons: Water Tribes – winter Earth Kingdom – spring Fire Nation – summer Air Nomads – autumn The cycle provides a natural balance between the elements.

This way, no single nation can grow stronger than another. Upon the death of an Avatar, Bending masters from the successive nation conduct a search to find the child reincarnate. (The successor is expected to show signs of continuity with the one who died, such as being born within a week of the death.)

These Benders carefully train the new Avatar to prepare him for his high position. First, he becomes proficient with his native element. Then, when the Avatar reaches maturity, he travels the world and studies with Masters from the other three Bending disciplines.

Upon completion of his training, the Avatar possesses sole control of all four elements. And so, the nations work to nurture the Avatar, whose responsibility it is to keep Water, Earth, Fire, and Air in harmony with each other and the world.

WHO STARTS THE WAR?

When a young, fearsome Firebender named Fire Lord Sozin ascends to the Fire Nation throne, only one person possesses the strength to oppose his rule – Avatar Roku, a Fire Nation native.

Many times during his reign, Fire Lord Sozin attempts to expand his empire, but the elder Avatar Roku always prevents his tyranny. Fire Lord Sozin’s only chance to achieve supremacy comes on the heels of Avatar Roku’s death.

Before the succeeding Avatar reaches maturity and challenges his action, Sozin secretly builds a massive armada of ironclad ships strong enough to overpower any nation’s Benders and trains a fierce army of Firebenders, foot soldiers, and assassins. For twelve years, the Water, Earth, and Air Nations live oblivious of Sozin’s hidden army.

Consequently, when the Fire Nation begins its assault, they are defenseless. Fire Lord Sozin strategizes to kill off the Air Nomads before the next Avatar grows to maturity. Strengthened by a passing comet’s natural energy, the Fire Nation simultaneously attacks the Water, Earth, and Air Nations.

Within one summer, Sozin’s Army wipes out the peaceful Air Nomads. Vainly assuming that the Avatar’s body lies among the casualties, Sozin expands his invasion of the valiant Water Tribes and Earth Kingdom; his devastation disrupts the natural cycle, ruins the delicate balance of the elements, and makes the Avatar’s future reincarnation impossible. Sozin envisions a world where Fire exists as the dominant element and no nation or energy challenges the Fire Lord’s rule.

Though he wages war for decades, Sozin dies before he sees this vision realized. Despite his death, he succeeds by inspiring greed for world domination among his descendants who continue to carry his torch and strengthen the Fire Nation’s hold on the world.

OTHER PHENOMENA

While a Master’s skill level determines the range of his attacks, his elemental power never extends beyond his immediate area. Therefore, an Earthbender possesses the strength to create a tremor locally, but not an earthquake five miles away. However, a Benders powers may be influenced by the seasons and natural phenomena.

Because each nation corresponds to a season, a Bender is strongest in his native land and during its season. Therefore, Waterbenders are strongest in the north and south poles, during winter; Firebenders are strongest near the equator during summer, etc. Benders are born into each nation, according to the season.

Therefore, Earthbenders are born during spring while Airbenders are born during autumn, etc. However, the number of Benders born during a season represents only a small percentage of all the children born.

While benders are frequently born to parents who also posses this power, it’s not uncommon for parents without powers to birth a Bender. Because of the lengthening summers, the Fire Nation births more and more Benders, while the other nations birth fewer.

Therefore, the Fire Nation’s conquest means disaster for opposing Masters. Seasonal changes will become non-existent. With the world stuck in perpetual summer, Firebender numbers will grow and strengthen, while Water, Earth, and Airbender numbers will weaken and diminish until they are extinct. In addition to the seasons, natural phenomena also influence a Bender’s power.

For example, the sun and comets strengthen Firebenders; the moon cycle and rain boost a Waterbender’s power; Earthbenders tap into the potential energy of fault lines; and wind and storms are advantageous to Airbenders.

The only thing that can rid a Firebender of his power is a total eclipse, which is short-lived and infrequent. Seasonal and natural phenomena play an important role in Avatar’s storyline as it relates to Benders.

On a sunny day near the equator, the kids take lengthy detours to avoid Firebenders. However, during cloudy, rainy weather, they travel a more risky, but direct route, relying on Aang and Katara’s heightened Airbending and Waterbending powers for protection.

The story is called Festival. Its set in a alternte timeline to our own but keeping its history. Its mostly wholesome with some dark elements. Also an "corporation manufacturing an energy crisis to keep poor people poor" type story.

Essence 

* An energized particle that has seeped from the Earth as a result of many fissures suddenly opening on March 15th 2012, all over the world in an event called The Splintering(where the Essence Timeline and Our timeline diverge). Since then essence has been used as a “perfect energy” source all over the world. This has helped the advancement of modern technology and medicine. In the years following, multiple lifeforms including humans were found with Essence naturally as part of their biology and multiple improvements because of its presence. 
* Such Subjects (dubbed “Outers”) exhibit abnormally efficient biology (better lungs/ oxygen absorption, more efficient immune system, etc) which allows them to access superhuman/superspecies performance. These Outers also possess the ability to manifest a special phenomenon. Each phenomenon and its effects are unique to each subject and are called Modus Operandi aka MO. 
* Do not confuse Essence for fuel for MO’s but the Key to them

Modus Operandi 

* Each MO is unique to each Outer and most likely no two Outer will have the same MO 
* The general way an MO functions is through the use of a Critical Formula = The mathematical symbolization of how any MO functions at its base level. This baseline use will provide the Outer with the most rudimentary understanding of how their MO works. 
* Using an MO doesn’t take any type of “energy” from the user but instead functions based on brain capacity. The Outers brain is the hardware that runs the MO’s code in order to function and the brain’s computational power sets the limit to which it can be used. Any MO has a limited amount of uses until it reaches BurnOut = a state in which an MO is unable to be used safely in regards to the health of the Outers brain. When in BurnOut, the user's brain is undergoing an excess amount of stress and starts to increase in temperature. The user will have to wait until their brain refreshes itself in order to use their MO safely again. This process can take anywhere from a couple minutes to days depending on the user's neuroplasticity.
* Another worry of Outers is BackFiring. When an MO is used too many times within a short window of time its margin of error increases by a varying percent. When this number reaches into the 80s, a backfire occurs. This means that no matter the computative power they are placed into BurnOut

Supplemental Numbers

* An addition to the Critical Formula in order to modify its use while not changing the overall effect of it.

Magnum Opus 

* A Magnum Opus is an optimization of the CF that the MO derives its ability from. This pinnacle is achieved via a deep knowledge of the components that make the CF work. Once it is achieved, 1 of 4 effects can take place: 1) The basics of an ability is taken to its maximum potential in a singular action. 2) The users form is temporarily changed in order to optimise the base ability. 3) An MO’s function is overextended to the point of creating another effect. 4) Some combination of the 3. 
* Once the Magnum Opus is deactivated the user is immediately placed on BurnOut but refresh time is reduced. This however will leave the Outer physically exhausted. 

Example:

Electrical Pylon

* Allows the outer to create a metal pylon at their location and use it to direct electrical discharges towards a target 
* This MO has two separate parts of its CF those being {0 = b\*sin(a)\*sin(b)/sin(a+b)} to summon the pylon to the user (with 0 being the users location) and {$E = V x Q$} to discharge electricity to its target.