"Don't think I'll let you get away with that!" Hai shouts and constructs a large magic circle directly in front of herself. "Maximize Magic: Compressed Fury Cutter!"
By further compressing the wind blades and amplifying the force vectors applied to them, Fury Cutter transforms from a dangerous trick into a natural disaster. Thousands of invisible blades cut through the air and shred the surrounding environment. Bark and soil fly into the air as the cone of devastation expands outwards from Hai's position.
"Hold!" Kobayashi shouts as the wind blades approach. Because the spell is expanding outward, running away will only cause one to receive more damage. Those without seals are doomed no matter what action they take, so the Baron focuses on saving those that at least have a chance. "HOOLD!"
Huge chunks of wood and dirt are gouged out of the forest by the powerful spell as it reaches the Duke's forces.
"Ahh!"
"GAAHHhhh!"
The cries of despair fill the air as dozens of soldiers die where they stand. Hai slowly falls to the ground as she struggles to stay awake after expending all her mana.
"We need to pull back for now." Rom grabs Hai by the waist and pulls her back into the forest as the humans begin counterattacking. Tiny limbs and wings fall to the ground as nearby fairies are hacked to pieces.
"We need to help!" Hai croaks, but she doesn't have the strength to fight against Rom now that her mana is depleted.
"We've done all we can for now. Let's pull back and live to fight again." Tears pour down her face as the desperately fighting children are slaughtered before her eyes. Many of the fairies in her squad were only born a few days ago. They never had the chance to fly through the flowers on top of the Mammoth Trees or bathe in the juice of a giant fruit as they ate their way through the center. They never made any friends or argued with their colleagues. They were merely born to die. The harsh reality of the forest was pressed upon them before they had a moment to consider it.
"I'll be back to save you. I'll save all of you! I won't let them steal your souls! I'll rip them all to shreds if it's the last thing I do! I swear it! I'll kill them all!" Hai screams and curses at the Duke's forces as she slips back into the safety of the forest.
Similar scenes take place all around the clearing. With Inari incapacitated and the squad leaders low on mana, the average fairy can do little in the face of the powerful knights. Foof watches the macabre acts being wrought upon his people, and a small smile slides up his face.
"Oh no, no, no," Duke Avaritan says while pulling himself out of the liquefied soil. "There's no smiling allowed here. Wipe that grin off your face. NOW!"
But Foof ignores him. The Lava Fairy simply floats up into the air, far out of reach of the one-handed Duke.
"Archers, Mages, someone, kill that fairy bastard!" The Duke shouts as he lobs his sword at Foof, but his blade misses and falls harmlessly to the ground. From his position in the sky, Foof surveys the battlefield. He takes a deep breath before focusing on the mana in the air and swirling the mana vortex inside himself. Part of his mana core is visible through the bloody stump where his shoulder used to be. The black orb begins glowing a deep purple color before vibrating violently. A tremendous amount of mana gathers at the center of the injured fairy, so much that he may explode if he loses focus for even a moment.
Slowly, a magnificent complex magic circle forms above his head. The shape of the purple structure is enough to captivate the eyes. Some of the soldiers below stop chasing after the fairies and look up at the circle above their heads.
"What are you doing?! Stop standing there and shoot him!" Duke Avaritan's shout pulls his men out of their stupor who then start chucking anything they can at the Lava Fairy. "Purple means that it's a soul magic spell! I don't know what he's doing, but don't let him finish that spell!"
While soul magic has a limited effect on monsters or fairies, as they are often an amalgamation of souls, this particular type of magic is devastating when used against humans. Its efficacy is one of the reasons it's banned by almost every country on the planet.
Several bolts of lightning strike Foof, but he ignores the attacks as if they were mere insect bites. A hail of arrows falls all around him, but he's so small that no one can hit him.
"His magic resistance is too high, sir! Our only option is to hit him with an arrow, but no one can hit a small target at such a distance."
"Don't you think I see that?! Just keep shooting if you don't want to die!" Numerous spells continue to slide off Foof as he constructs the magic circle. A dull purple aura fills the open area. "Goddammit, kill him now!"
A single arrow breaks free from the pack and hurtles toward the lone fairy in the sky. Like a heat-sealing missile, the steel tip of the arrow strikes Foof directly in the center of the chest.
"We got him!" a nearby Captain shouts.
"Wait, what the hell?" Despite all expectations, the arrow falls harmlessly to the floor. A small magic circle spins at the point of impact, which negates all the force. The Duke continues raging when he sees the failed attack. "What the fuck?! When did he have time to prepare a second spell?! I already cut off one of his arms. He should only be able to cast one spell at a time!"
[Unless he's been casting spells simultaneously in his head this whole time.]
The last part the Duke keeps to himself because it may be the terrifying truth. Normally, people have shortcuts for simultaneous casting, like preparing a spell beforehand with a scroll or tattoo. Some people can cast spells very quickly and make it seem like they cast two spells simultaneously, while others will go back and forth, partially constructing one magic circle before moving to the other and then back again. In this case, the Lava Fairy was clearly casting a soul magic spell the entire time, meaning he had to construct a defensive spell simultaneously. The technical difficulty required to do something like that is off the charts. It'd be like drawing two pictures simultaneously while also saying two separate sentences in two different languages. You'd basically need two bodies to pull off something similar. The Duke shivers slightly as a chill runs down his spine at the thought.
[No matter what, we have to finish them off here. We can't let them continue to grow.]