*BAM* Explosion sound.
"It's huge," Willow mutters.
I ignore Willow's words and simply change instruments, switching from an enchanting melody to eerie music.
The air has become heavy; I can see Willow is struggling to breathe. So I need to control my magic even more to focus it on the lake monster.
"Haaaa!" the creature screams.
Something seems to be forming on its body, this thing wants to come out despite the monster's attempts to keep it inside.
This music is no longer a replica of Sorrento, a general of Poseidon, but a slightly different version of Pharaoh Sphinx's song, who is a specter of Hades.
Pharaoh's music torments the heart of the listener and forces it out of their chest to make them perish. Mine is slightly different.
The target's heart is violently tormented due to its owner's anguish. It's like a genjutsu, but it's not the mind that's targeted, it's the brain simulating enormous stress itself, and the heart will eventually give out.
This is currently my second most dangerous bard magic attack. The first one targets not just the body, but also the soul and spirit.
While playing, I glance at Willow, who seems shocked by the huge monster begging its heart to stay in its chest.
"What are you waiting for? You want it to suffer even more?" I ask, frowning.
"Sorry!" she says quickly before drawing her sword.
I can see that Willow is focused, her eyes glowing with a green light, a sign of her Grand concentration. She takes a few breaths before being propelled towards the dying monster with the help of plants emerging from the ground.
"Secret Killing Move - Cross Slash!" Willow shouts in the air as her sword glows. It's a secret technique of the Farlier family.
Cross Slash is a technique that combines the essence of various deadly skills gathered by Leylin Farlier with the help of his AI chip.
It requires using a high skill level to enhance the killing power of the attack with life energy.
Then you need to quickly execute a vertical cut followed by a horizontal one, creating a luminous cross with the merged strikes.
"Haaaa!" the monster's final scream.
"You could have just aimed for the head and not the chest," I say, looking at the X on the sea monster's chest.
"I didn't want to take any risks," she says, referring to my estimate of the monster's power.
"I see, good job," I say sincerely, looking at the monster's destroyed heart.
I approach the monster, ignoring Willow's strange noise after my compliment. I need to start the ceremony to capture its soul in a crystal ball quickly.
Before its soul is called back into the reincarnation cycle, and Willow needs time to prepare the magic formation, or in our case, the tattoo that will seal the creature's soul.
The witches of the Boiling Isles have long been imprisoning spiritual beings in objects, and I was able to do something similar back when I was even younger.
I start using my musical instrument to attract the creature's soul towards the crystal ball.
"Willow, you'll do it the next time alone, but today I'll help you," I say, playing soothing music. Willow seems to want to say something but ends up staying silent.
She must have understood, thanks to the information I sent her on the way, that she won't be able to seal the lake monster's soul herself.
She wanted strength and I'm giving it to her, but she's risking her life.
The monster's soul in the crystal ball feels resentment towards Willow. I need to use my Oracle magic to chase that away, but also to enchant it using bard magic at the same time.
The soul of monster must be cooperative to end up sealed in the magic formation that Willow is currently drawing on her hand.
It's a complex magic formation but much simpler than the one traced by Leylin Farlier. It's a rank 5 beast spirit formation, or more precisely the first level of this formation.
If Willow wants a more powerful beast spirit, she'll have to upgrade it, but she'll be able to capture other spirits of the same level as the lake monster, like a giant bat.
At the heart of this magic formation is a twisted pentagonal diagram and many soul runes giving me a feeling of mystery and savagery.
These are essential for mastering beast spirits, and have even led the latter to turn against the master of beast spirits.
The rays emitted by the magic formation on Willow's hand envelop the lake monster's spirit, and the small lizard trapped in the crystal ball is released and begins to float.
Throughout the ceremony, I continue playing to calm the monster soul's hatred against Willow and me.
"It's time!" I say urgently. The small lizard representing the lake monster's soul is above Willow's hand.
After hearing me, Willow understands that she needs to act and seal the monster.
"Normally, this would be a battle between your soul and its, Willow, but I'm going to intervene once again," I say, pulling out the Memory Gun.
I set it to target the monster's entire memories. I've already soothed its hatred, but its memories push it to refuse Willow as its master.
"Welcome to the team," I say, pulling the trigger to erase the memories of the monster currently confronting Willow in her mind.
After my act, I can feel an enormous pressure emanating from Willow.
It's not magic, or to be more precise, there is magical energy emanating from Willow, but also a familiar energy coming from her.
It's the same as when I met Leylin Farlier back then, despite his baby state.
"An advancement to a rank 1 magus!" I mutter, pleasantly surprised.
I need to move her quickly, she's giving off too much radiation.
This place risks becoming harmful to ordinary people for the next decade.
...
"I'm pleasantly surprised you didn't run away," I say, returning to the Mystery Shack.
I had deposited Willow in the bunker; she's currently in a trance.
I can't intervene during Willow's advancement process; I can just put her in safety.
Her advancement must have been triggered by the sudden gain of spiritual energy provided by the monster's soul.
Beast Spirit Masters are nourished every second by the energy emitted by their Beast Spirit. Willow was probably at the peak of acolyte rank 3.
I left some abominations to watch over her in the bunker, but also a surveillance crystal ball. I'll be able to know if an abomination is destroyed and I'll be able to see if there's a problem.
"So you're back," Stan says in a clearly hostile tone, looking me up and down. He must have noticed my new clothes created from abominations.
The old ones were too exposed to the radiation emitted by Willow; I could unintentionally hurt an ordinary person with them.
Author's Note: I really had to reread a good part of the purgatory world arc to write this correctly.