I became a legion lich

81 Invading the forest

The next day, at noon.

Since fighting the mage slayers, Treevor has spent all his time inside the cave trying to fix the amber gem enough that he can flee beyond the reach of humans. According to his calculations, he would need only a week to reduce the energy leak enough to escape this forest, but where he would go and be safe was a mystery to him.

As he thought about where he was going next, Treevor felt something strange approaching the edge of the forest. It was a repulsive feeling that made him want to throw up, but he’d gotten used to feeling it in the last few days.

“Did that filthy undead return to the forest? But why?” Treevor wondered. He was in his elven body, not wanting to burden the willow unnecessarily. He touched the roots to the ground with his right arm, making him connect with the roots as if they were merged and his amber eye glowed, shifting his awareness to the edge of the forest.

What he saw was shocking to say the least. 4000 undead lined the edge of the forest, with those in front carrying torches in their hands. A skeleton wearing the mage slayers attire stood in front of them, mounted on a rock bear.

“Did that skeleton kill so many people in such a short time? Are human cities so weak that a few dozen undead can destroy it that fast? Also, he somehow managed to kill one of the invaders’ survivors, so he must know about me and yet dare to invade my forest?” Treevor wondered in confusion, unable to understand how Athos had gathered so many skeletons in such a short time.

But that was it. He felt no threat from the skeletons, just surprise and a slight annoyance at having to deal with these skeletons when he needed to muster the energy to escape.

“Do they want to burn the entire forest? They must already know that I can control the forest from a distance and stop any fire. So what’s the point of all this futile effort?” Treevor wondered, but didn’t stop making preparations.

‘I could attack them while they’re still far from the forest, but I don’t know how many undead he has and I haven’t seen that lead skeleton yet, so these must be just a forward team, the real enemy must be watching from somewhere. I’d better let them burn the trees and enter the forest, then regenerate the trees behind them and kill them all at once.’ That’s what Treevor thought.

.....

He patiently waited for the skeletons to invade the forest, but strangely, all the skeletons stopped a few feet from the tree line, as if they were waiting for something.

‘What are they doing?’ Treevor wondered, as if the answer would simply fall from the sky. And a few seconds later, it really did. A strange liquid began to drip onto the tops of the trees where the undead were waiting, surprising Treevor.

He focused his attention on the sky, but all he felt was liquid being spilled. His ability to sense the surroundings of trees didn’t mean he could actually see things, it was more akin to Athos’ sensory field ability, allowing him to sense approaching objects, whether physical or magical in nature.

It also meant that anything above a few feet of treetops would go unnoticed by him. It was a happy coincidence for Athos, but an annoyance for Treevor. The latter returned to consciousness to his own body for a moment and looked up to the sky, immediately understanding the enemy’s plan.

Skeleton birds were flying above the forest as they held canteens, spreading the liquid across the forest. Athos had ordered the skeletons to gather all the flammable oil in the city and put it in canteens, before ordering the birds to pour it over the forest.

One of the most expensive and best-selling products during the winter was flammable oil, used to heat homes, and there were whole barrels in the carriages of the wealthy merchants that Halt stole.

The skeletons moved in unison as the oil spilled into the forest, flinging the torches as far as they could. The flames came into contact with the flammable oil, igniting instantly. The fire spread quickly, burning half the forest. The heat wave spread so fast that even Treevor felt the heat in the distance.

‘Intelligent. The oil won’t be fully consumed right away, so even if I erase the heat, it will light up again. Smart, but not good enough.’ Treevor thought, his amber eye releasing a pulse of energy that spread up his arm to the willow tree behind him. The willow leaves glowed with white light, absorbing the light element around them, before being amplified by the willow itself and spreading through the forest.

The light spread over the burned trees, but did not heal them, instead creating a thin layer of light over the trees. The layer of light did not allow air to pass through, smothering the flames until they died out. The temperature was still absurdly hot, but the cold of winter would make the temperature cool quickly.

‘With that, he should charge with brute force or at least send the first wave-‘ Treevor thought, until he saw a second flock of skeleton birds approaching from the forest. They also carried something in their paws, but the bottles were glass this time. Treevor felt irritated, imagining the undead wanted a battle of resistance against him.

This time, they just dropped the glass bottles once they were above the forest. The glass bottles shattered when dropped to the ground or trees, releasing a viscous green liquid that immediately began to sizzle and melt anything it touched.

‘Is that acid? Shit!’ Treevor thought in confusion for a moment, before realization hit him a second too late. The acid wasn’t just sizzling from corroding the floor, but also because it was evaporating from the high temperature. Athos had hunted the sewer slimes, gathering enough acid to melt an entire fortress.

Slime acid was extremely corrosive and had an even lower boiling point than water, evaporating easily in the heat of the forest. A corrosive fog quickly formed in the forest, corroding everything it touched. Even the protective light layer was useless. Even the protective layer of light was useless, only delaying the acid for a few seconds before disappearing.

“Fuck!” Treevor swore loudly, feeling the trees being destroyed in quick succession. He didn’t have any defensive measures to deal with a corrosive fog, so he could only watch helplessly as his forest was destroyed. as the cloud spread, his mystical senses grew weaker and weaker until he became unable to sense anything in the area near the skeletons.

“These bony bastards are smarter than I thought. I better prepare to fight just in case.” Treevor spoke, his tree arm breaking away from the roots before he touched the willow. The willow swung open as if it recognized it and Treevor entered, before quickly closing behind him.

The wooden face appeared at the base of the tree, before moving to the top to observe the corrosive cloud. On the other side of the cloud, outside the forest, two skeletons took a step forward before a black wind gathered around them. Both wore the order’s green cloak, but one of them was wearing an iron sword, while the other held a wand in his hands.

They conjured a gale that slammed towards the corrosive cloud, pushing it toward the center of the forest, where Treevor was.

“Now, attack!” Athos screamed, causing the undead to invade the forest now that there was no risk of being corroded.

‘Now, be aware and wait for an opportunity.’ He mentally ordered, causing Finn among the other skeletons to nod his head. The black skeletons advanced as fast as they could, the terrain now clear of impediments.

“You annoying son of a bitch...!” Treevor swore loudly, seeing the corrosive cloud being guided towards him and the hundreds of undead running close behind. He cast his glacial winter spell, lowering the temperature around the forest by -50oC. The acidic cloud quickly grew heavy and became liquid again, harmlessly eating away at the ground.

‘Partial assault form.’ Treevor thought, transforming willow tree upper part into its attack form. It was a necessary measure to save energy and prevent energy leakage from the gem. His body was approximately 8 meters, but his energy was much less than before and even more spread out, so his power dropped.

Treevor didn’t even summon the gem, purely using the power he naturally draws from the environment to supply the core’s own transformation and mana to cast spells. The willow needed to remain connected to the ground to extract world energy, making it an easy target.

The undead ignored the extreme cold and quickly reached the edge of the artificial cave. They looked down and glared menacingly at Treevor. Their absurd numbers completely surrounded the cave. Treevor sneered at them, as if he saw rats invading his backyard.

“Think you can kill me with those bunches of ants, undead? Know that no matter how many ants you gather, you’re just insects!” Treevor yelled, looking straight into Athos’ eyes. Now that he could look at the undead up close, his mystical senses showed how the souls of the dead were bound by black chains. The chains were attached to certain skeletons, but all chains ended in a single undead.