Yuusha System
Origin - Yuusha System
Heroes of the Taisha are young girls empowered through the Hero System to receive the blessings of a divine tree, the Shinju-sama, which protects humanity from the threat of the Vertexes in exchange for sacrifices. In the case of these Heroes, the sacrifices are the bodies of girls engaged in the fighting. As they use their powers, they progress through a cycle called the 'Sange', in which they grow in power in the same manner as a flower matures. At the end of this process, the Hero's power swells to its greatest peak, undergoing 'Mankai'. Then, their blossom drops, and another takes its place.
Unfortunately, the 'blossom' in this case is the part of their body. It may be one of their senses, a limb, memories, or a capability (like speech). But this price is always paid for going through Mankai. Furthermore, the 'Fairy System' uses servants of the Shinju-sama to cooperate with and protect the Heroes from serious harm. They may be hurt or injured, but they can never die, no matter what state they wind up in.
The job of the Fairies is to bind the Heroes to their duty, granting them a status of semi-divinity to the Taisha, but losing important elements of personhood.
The Heroes of the Taisha utilize an application on their phones that allows them to communicate with each other, locate each other, and identify and track Vertexes when they appear. The phone also provides them with a warning when a Vertex attack is imminent, and conveys them to the Shinju-sama's barrier, a separate dimension from their own.
The longer a Vertex is allowed to roam about unchecked, the more damage is inflicted to the Shinju-sama and is then reflected in the physical world. Thus, sealing and defeating Vertexes as quickly as possible is important to avoid casualties. The Hero's phone has detailed instructions on how all of this works.
If someone is no longer needed as a Hero, their phone is taken by the Taisha, and they are given another one without the Hero System on it. As well, if a girl loses the will to become a Hero and fight, then they won't be able to transform or use their powers.
The Fairy System, however, will work whether they are transformed or not, whether they will it to or not, and even if their phone is completely drained of battery the Fairies will still appear to protect them... No matter what.
The Heroes of the Taisha transform into elegant crosses between dresses and armor, with weapons either built-in or summonable as-needed. Aesthetically, while each one is different and unique to the user, they have a similar flower theme throughout, depending on what flower is associated with the Hero in question.
If a Hero is disabled or incapable in some way, their outfit will have accommodations to allow them to fight regardless, but does not physically replace the disability or allow them to use something they have lost. Each Hero has a different combat range, whether that is long, intermediate, or short. Their weaponry tends to reflect this, as does their fighting style. A melee-range Hero will fight with hand-to-hand attacks, while a sniper will attack from ultra long range with projectile attacks.
And, of course, all Heroes are able to progress through the Sange, achieve Mankai, and transform into a sort of super-powered version of their Hero form, with all of their abilities and weapons amplified to extraordinary levels... At the cost of their bodies.