We are not alone. Matter of fact, there are four known realities out there.
Terria; the world of the humans, of course, but there are 3 others. The beings of these realities became the bases of our world's myths and legends. Throughout history we have been visited by beings from these other worlds. First, Titan; a world of beings with wings and a bright glow about them. The ones who visited thousands of years ago were called Gods and Angels. Every once and a while a being from Mythios is seen. That's where we get legends of Unicorns, Dragons, Elves and Ogres. Gehenna is the fourth reality and it's the world of the demons.
A little over 100 years ago, an anomaly occurred that opened paths to each reality. Upon that event a revelation occurred on Terria, that these myths and legends were not gods and devils in the sky or some hell, but actually living beings in their own worlds.
The people of Titan, mostly keep to themselves not wanting to be bothered by issues of humans. Mythios and the human world tend to have an uneasy kinship. With beings of both worlds visiting and even living in the other's world. Even though there are purest who don't believe in the mixing of the groups. But ever since that anomaly, Gehenna has been a huge threat. Demons from Gehenna would cross onto both Terria and Mythios, creating havoc, destroying cities, eating animals and people. It got so bad, that with help of beings from both Mythios and Titan, the humans created 2 defenses against the demons of Gehenna.
First Elves from Mythios taught humans magic, which made a defense force of sorcerers and sorceresses. Then the people of Titan taught humans about Ki energy, a force within every living thing. That with practice and training, someone who is Ki sensitive can manipulate and even weaponize their Ki. Even using it to heal themselves. The people who learned Ki abilities became known as Guardians. Sorcerers and Guardians went on to protect the human world for over the next 50 years, but even with them doing their best, the demons still wreaked havoc on the human world.
That is, until she appeared. Lunaclipseia the most powerful Guardian ever. Her abilities rivaled those of some of Titian's most powerful, not only was she able to manipulate her Ki on herself but on others. Healing them and making them stronger. Lunaclipseia was powerful enough to eliminate a mid level demon with little effort. Her strength brought great power to the human world, her strength and even managed to get the attention of the 3 Demon Lords. Particularly the attention of Balthazar, the Demon Lord with the desire to take sole control of Gehenna and Terria.
Balthazar deployed a plan that led to the capture of Lunaclipseia. With her in his possession he planned to use her abilities to make himself strong enough to kill the other 2 Demon Lords of Gehenna. Then use the forces of the 3 kingdoms to take over Terria. But, before Balthazar could use her, Lunaclipseia sacrificed herself using her Ki to create a barrier around Gehenna. To keep the demons trapped inside and with her last moments focused her innate Ki abilities to be reincarnated.
It's been 16 years since that day and a girl, who unknowingly holds the reincarnated abilities of Lunaclipseia, is going to soon awaken that power. Her name is Luna named after Lunaclipseia, who is regarded as a great hero in Terria. This is the story of her awakening and the adventures that comes as a result of her hidden power.