Stars Under the Oni mask.

Chapter 6: objective completed,

Grim stood at the mouth of the cave and gulped. Hesitant of his role in the plan. The little monster yelled into the cave to lure the inky beast from the depths. The monster responded by emerging in a rage. Grim panicked at the sight of it.
"YUU! HELP!," the grey feline monster screamed, his blue flames shining.
Hoshi jumped from her hiding spot and used both pickaxes to strike the monster, tearing at its slimy flesh. She had a little trouble breathing, but did not let that shake her as she landed the powerful hits onto the beast. The monstrous abomination roared at the strike and swung its own Pickaxe to hit her, screaming that it would never let them have the magic crystal.
"Yuu! If we get hit, we'll die!," Grim wailed.
The girl avoided another swing from the monster, barely missing being struck by the lantern like growth on it.
The masked blonde teen ran with Grim following her, "Then let's not get hit. We need to lead it away from the cave long enough for this to work."
She removed the broken Magic crystal from her pocket and held it up for the monster to see, it more than likely did not have much mental power based on how animalistic its attacks were.

The monster followed her after seeing the crystal in her possession. The young woman saw the other two getting into position. The monster got closer and closer to her. After getting the black inky beast away from the mine, she held the pickaxes up to signal Ace. The scarlet eyed redhead summoned up a large gust of wind as Grim summoned a wall of flames. The combined magic whipped up a blue flaming tornado that trapped the monster in it. Hoshi's laughter mocked the monster. With her mask, she seemed absolutely mad.
"Taste our burning determination!," She howled with laughter.
The bells on her mask chimed with an eerie ringing sound. The blue fire lit up the teens and Grim's bodies.
"Look at that, my wind made Grim's feeble flames into a raging inferno!," Ace laughed.
Grim huffed, "Whatddya say?!"
"Not now, you two.," the blonde teen interrupted the two, "Deuce! Your turn!"
The dark blue haired young man took a breath and took aim, "The largest and heaviest thing I can think of.  Keep calm."
Deuce thought of it and held his hands put to the monster, "I summon thee! Cauldron!"
From above the monster, a huge black cauldron appeared. The massive cooking implement fell onto the monster. The monster was trapped and flattened by the cauldron.
"Now, go!," Hoshi yelled.
The group went into the cave quickly. The girl used her pickaxes to cleave at the rock around the crystal. Deuce grabbed another pickaxe and helped her. The roars of the beat increased as it was forced to watch the precious magic stone formation be mined. It began to struggle free from the restraints. It was almost out when Deuce noticed and summoned cauldron after cauldron to pile on top of the beast. Ace took a pickaxe from Hoshi and swung it to help free the stone from its confines.
"Is that the only thing you know how to do?!," Ace shot at the other young man.
Deuce did not take too kindly to that, "I'm already worked up, don't make me even worse!"
Grim shot a large fireball mixed with plasma, breaking the rock around the magic crystal.

"There! It's out! Now let's scram!," the blue eyed monster exclaimed.
Hoshi picked up the stone and put it in her pocket. The group ran as fast as they could out of the cave. They passed the monster as it cried out for the stone. But the teens did not stop. They made their way back to the cabin near the mirror gate. The masked girl saw a mirror mounted on a cliff face, their way back! Her relief gave way to more panic as the roars of the monster that was following them in a rage.
"Are you kidding me?! That damn thing is still coming!," Ace cursed.
It was catching up to them very quickly for an inky mass with no legs. Hoshi felt the adrenaline hit as she got her second wind. This adrenaline spike made her feel even stronger than before. Another feeling came with the adrenaline, she wanted that monster dead. It had almost killed her multiple times while she was trying to keep these boys in school.
"There's no choice then. We're gonna kill it!," the blonde teen yelled as her mask slip up a bit on her face, causing her voice to project louder and clearer.
"I'm right with you on that!," Deuce said in his delinquent voice.
"Let's send this bastard straight to hell!," Ace agreed.
Grim seemed to have his previous fears melt away, all of them felt it. It was all or nothing and their hearts seemed to feel each other's rage towards this monster that stood before them. Hoshi exhaled a breath violently and took a deep one. Grim exhaled blue flames as his fighting spirit flared with the other three.
A bond seemed to have been formed.
Hoshi avoided being hit by the pick that was swung at her and used the beast's now stuck arm as am opportunity to strike with the sharp pick she was holding. The power of her swing caused the pick she held to get embedded in the body of the monster. She let go of it and jumped back to avoid getting hit by the swinging lantern.