Sealing Crystal
It is said that the soul is made of pure Aether and it can be manipulated like as any other magical energy, though with some difficulty. This means that pieces of or the entirety of a spirit can be stored inside of Aethercite.
Humans throughout history have abused this quirk of the soul and have forced the souls of powerful mages inside of aethercite crystals to be abused to the day their spirit falls apart and ceases to exist. A notable example of this is a legendary weapon, the Shattered Sisters and the remains of that sword, Ki, the Crystal Shield.
More commonly, people use aethercite crystals to seal away especially powerful Incoporeal beings such as spirits, demons, and wraiths, which are classified as bodiless souls on Vreathe. Normally, this requires a special piece of Aethercite called a Sealing Crystal, which is usually a diamond or Moissanite crystal.
the Vernador family, being descendants of Saint Nora, have the ability to sense spirits and their magic is able to manipulate spiritual energy as easily as any other magical energy. They can seal away powerful spirits in just about any aethercite crystal they happen to have at the time. Any crystal to them is a sealing crystal. This will alter the properties of the aethercite, turning it into an entirely new form.
Story
The Demon lifted its arms and laughed, "Hee-hee-hee! I'm in luck! I've been trapped for a thousand years waiting for a Vernador to kill, and one just happens to be near when I finally made my escape! And it's just a little girl!"
The Demon laughed again, "I'll kill her, I'll eviscerate her, I'll skin her! I'll violate her in any way I can image, then I'll bring the corpse to the parents, then kill the parents!"
"Uhm... I'm standing right here," Saya said, "Also, my parents are dead, and I'm not a Vernador, I'm--"
"Oh?" The demon interrupted Saya. It lowered his arms and then made a crude bowing gesture. "So are you the Queen of these lands then? All hail Queen Vernador the... er, what number are you? Twenty? Twenty five? Doesn't matter! I've been trapped for quite some time and I don't really care how many of you there have been!"
"Queen!?! No!" Saya shook her head. She knows that technically, she is the ruler of these lands, but... That was not worth thinking about right now when a demon is about to attack! Saya raised her sword in her right hand and charged magic in her left. She took her stance and waited for the demon to attack.
"Then there must be another Vernador in charge. I'll bring your remains to them then!" The demon's spectral form started twisting in unpredictable ways as it charged towards Saya, hoping to get the first blow. Saya expertly raised her sword and parried the demon's claws several times, but she wasn't fast enough to block all of them. One of the demon's claws went around Saya's sword and swiped at her arm, ripping the fabric and digging into her flesh. Saya screamed out in pain.
The demon then made several more attacks that landed on Saya, including on her face. Saya was able to barely escape serious damage from these attacks. The Demon swung with all four of its arms at the same time, gripping Saya's sword, hoping to rip it out of her hands and leave her defenseless. This provided an opening.
Saya sent off a charge of magic, causing a bright light to cover the courtyard. The Demon shielded its eyes, giving Saya a precious few seconds to safely retreat. When the demon was able to see again, it noticed Saya kneeling on the ground several yards away. She was using magic directly on her arm, healing most of the damage that was done.
"I'll admit girl, you have skill with a blade and skill with magic!" The demon raised its arms and darkness started to spread from them, "but it will not be enough to defeat me! For I am Lorgomarth, Seventh Son of Tragnaro, Scourge of the North, The Evil of Orthez, Bane of the Vernadors, Veil of the Red Towers, Arch Demon of..."
Saya's ears were ringing. Her face was bleeding, she was in pain, and the Demon just kept talking! This did allow Saya to think of what to do in this situation. She pulled a crystal out of her pocket. It was a dark green emerald. Saya started charging it with magic.
Lorgomarth stopped talking when it noticed the glowing gem in Saya's hand. It laughed, "Girl, do you think YOU have the power to seal me? It took an army to seal me! What would make you think you're special?"
"Nothing at all!" Saya laughed, "I'm not even a Vernador anymore. My Name is Saya Diaz! But to take out someone like you, I'll be a Vernador again, for now!" Saya lifted the emerald into the air. It was glowing so brightly it illuminated the entire courtyard and was almost white.
"What!?! No! Where is this power coming from!" Lorgomarth demanded, "You're a human, a child! You can't possibly have the mana to sea me!"
"Mana? I've never had a problem with that! Well, Xana made sure of that!"
"Xana!?! You have a Bloodpact with a fairy!?!" Lorgomarth visibly shook. It then started charging orbs of dark magic in its hands. "No! I will not be sealed again so soon! I will kill you!" Lorgomarth threw the orbs at Saya. They exploded into crackling energy, but Saya was unmoved.
When the Emerald in Saya's hands changed fully to white light, it flashed, glowing brighter than the sun, glowing bright enough to blind anything looking directly at it. The demon was engulfed in this light, screaming in agony it struggled against the power in the crystal as its physical body burned away. When the flash of light ended, the courtyard returned to normal. The emerald was now unnaturally glowing red.
Saya then fell to her knees, cut, bloodied, and fully exhausted from this short fight. Saya had successfully sealed a wraith. Even powerful elven mages have trouble fighting such a monster. She should be proud, but she was not, because she used the abilities of a Vernador.
"I am not Vyerin Vernador!" Saya wanted to yell, but only barely eeked out a whisper. "Not anymore!"
Amazing