Hello and welcome to my RP idea!
I hope it catches on...

Basic rundown right here, the setting is a parallel world - think Final Fantasy in terms of environment. Epic castles as the major focal points of cities, taverns and pubs, apothecaries and the such, a medieval setting with almost modern technology such as ballistic bows, catapults with laser targeting, etc. Use your imaginations

Here is the interesting part - There are three magic types, Hereditary (where the magic is inherited biologically) Earned (where it is gifted after doing something for a deity, demon or entity or some sort, kinda like a powerup) and Contracted (a contract is signed with a god/demon/entity etc, and powers are received in return for servitude).

Each has it's own strengths and weaknesses:

Hereditary: Hereditary powers tend to be the strongest. Being naturally inherent and growing alongside their user from birth, Hereditary powers tend to have the strongest capabilities. However, they can be magically blocked by trap sigils, silenced by wards, or restrained by warpstone. (These three are elements I will reveal later.)
The most interesting - and violent - thing about Hereditary powers is that they are vulnerable to a process called Mangling. If a Hereditary magic user is Mangled, their power can be taken from them. If they are Mangled by another Hereditary user, their powers are in fact swapped. This means that Hereditary users must watch their backs constantly, lest they fall prey to a jealous rival or a magical thief.

Earned: Earned powers tend to be the least amazing - the level of the quest affects the level of the power received, and so on and so forth. As a result, whilst a Hereditary user of flame magic may have the ability to incinerate entire buildings, an Earned mastery of flame may only be enough to heat up individual objects, etc - far more subtle powers. However, Earned users have a colossal trump card - their powers cannot be blocked, hindered, halted or lessened in any possible way, meaning that you can never underestimate one; that is, unless you want to get your ass kicked.

Contracted: Contracted powers are the most violent. They usually have some sort of agenda or reason for the contract, due to the fact - and by far the most interesting magical aspect - that one person can have an unlimited amount of contracts in their lifetime, and if one contract is terminated, the user is free to pick up another one if they can find a place - and a client - to make one. In terms of power, they have the middle ground, capable of the flashiness of Hereditaries and the effectiveness of Earned powers - but with one major weakness. In order for a contract to be used, the contract must be carried on one's person, and they are always extremely fragile. It is a great risk for a Contracted user to engage in an uneven fight, as the contract being destroyed would leave them completely defenseless. Considering that Contracted can terminate their own contracts at will in order to select other ones, Contracted tend to seek specific powers to counter and terminate specific foes.

Other important facts

- All three users can learn how to Mangle, but only Hereditary users have their powers switched as a result of it.
- Contracted users cannot Earn magics.
- It is technically possible for an Earned user to Mangle Hereditary powers and use a Contract at the same time. However, upon acquiring Hereditary powers their immunity to blocking mechanisms would be removed, and an Earned/Hereditary user can only use ONE contract in their lifetime.
- Hereditary users can only Earn abilities if they have been Mangled recently.
- Earned users have the ability to further Earn more powers, but only if they are not Contracted OR have Mangled recently.


Races:

There are five potential races to choose from. The races are not just purely cosmetic, as each race possesses a natural magical trait that they can use independently of their magical affiliation:

Human, Elf, Deserter, Filthborn and Stonekin.

Human: The stereotypical race, possessing no real advantages or disadvantages, a resourceful industrial race who have colonized the surface world. (You all know the drill )
Trait: Trap Sigils - they can conjure 8-foot tall and wide sigils onto any surface. Only one at a time. If Hereditary or Contracted magic is cast whilst in contact with a seal, the magic is negated and the caster is trapped for five seconds in an inescapable barrier. No magic may enter or escape the barrier for the duration of the trap.

Elf: A peaceful wood-dwelling race, elves have been forced to come into contact with men due to their rapid exploration of the world. Fascinated by their doings, the elves and men have learned to co-exist.
Trait: Warding - By focusing on a particular location in their heads, elves can magically gain vision as to what is happening at that location. A person will know if they are being warded, as they will be unable to use magic for as long as the elf maintains absolute concentration or until they leave the warded area.

Deserter: A race that sprung from humans exiled into the harsh deserts, Deserters have recently regained civilisation's trust and can see the value in co-operation - though they are hardy as a result of their up-bringing.
Trait: Keening: Deserters possess an unnatural ability to sense warpstone, a magical rock that robs magic users of their powers. This can permit them to either find it on their own and utilize it, evade it as a trap, or turn their enemy's "surprise" to their advantage.

Filthborn and Stonekin:

These two share a history - when elves and men, with the help of deserters, found a gigantic mine of warpstone, they both sent a coalition force down to mine the stone out for study and usage in the cities. However, a terrible accident caused the entrance to collapse, dooming those within to be trapped without any hope of rescue or escape - magic does not work on warpstone, and no-one could Earn enough power to free those within fast enough. Those within had to make a choice for survival - whether they fled deeper into the mine, hoping to discover some natural passage to the surface if they searched far enough, or followed the winding long river that was their only source of water back however far it went in order to escape at it's source, which could be infinitely far away.

Those that followed the river became the Filthborn, whilst those that ventured further into the mine became the Stonekin.
The river reacted with minerals in the warpstone to release a strange miasma that mutated and disfigured those close to it, morphing the former men and elves into hideous blistered monsters. By the time they had discovered an escape route, their future children were stuck with the same curse, and it carried on throughout the generations.
Trait: Bioarcanity - Filthborn have the ability to negate poisons, toxins, indefinitely hold their breath and walk underwater as well as being able to negate the feeling of pain, simply by shutting their eyes.

Meanwhile, those that trekked deeper into the mine came across pure warpstone, untainted by earthly minerals. Exposure to this substance for a prolonged time caused the unfortunate miners to develop the incredible ability to turning anything they touched, that wasn't organic, to stone. They took a LOT longer to escape than the Filthborn, and two generations of Stonekin were born by the time an exit was discovered from the mine. By that time, they had mastered their ability, and the youngest Stonekin was capable of rendering a matchstick indestructible from even the sharpest sword with a single touch.
Trait: Augmentation - Stonekin have the ability to change the composition of any inorganic object they touch to harder than the strongest steel. This lasts for only as long as the Stonekin is in contact with the object, and they cannot change two objects at the same time.

In order for a plot to keep things moving, the focal point of the story is a wild and reckless Hereditary user who has access to the titular First Power - flight, superhuman speed and strength, and indestructibility. (I will be playing his younger brother, who only has access to the second power, flight, but is looking to save the world from his devil-may-care sibling, whilst watching his back whilst his younger brother and sister - who have super-speed and super-strength, respectively.)

Sorry I gave you a lot to read, I hope you enjoy it, HAVE FUN!