Taming my Monster Girl Harem from Scratch

Each step of the cyclops covered dozens of meters. At its pace, it would reach Fang in just a few seconds. I, on the other hand, was blasted far from Fang's position. No matter what I do, I can't reach them in time.

With nobody in the group who can fight an 8th-level demon, only death awaits them. That's something that I can't allow.

"I promised to keep my girls safe!!!"

I shouted as I started circulating the energy inside my body at higher speeds. Across my skin, black lines tracing the veins all over my body appeared. Smoke started rising from my skin as the energy inside me heated up my whole body.

This technique was an improved version of what I used back when we ran away from the Void Eater, and I named it Lifeblood. It's one of the forbidden skills I developed in the black space that I managed to recall earlier. 

I forbid its usage since for every second I spend in this mode, the life force equivalent to 10 days of my lifespan gets snuffed out. The drawback was too big to even consider usage; however, it will raise all physical abilities to the limit, allowing one to exhibit almost god-level performance.

I took a stride forward, and the rocks that I stepped on turned to powder in an instant. In a flash, I was already behind the Cyclops. Using the momentum of my dash, I kicked the cyclops' nape, sending it smashing toward the ground.

"Owl, protect everyone for a moment, and don't move!"

I shouted as I moved closer to them. The wolves I passed by were sent flying by the air pressure released by my movements. I turned around, facing everything that was right before me.

I drew my sword and prepared it in a stance.

"Come!"

I shouted towards the cyclops, which was still trying to get up. Its singular eye stared at me in anger as it roared. The air vibrated wildly, sending the wolves nearby to their deaths with that alone.

Thirty seconds have passed. I've already lost about a year's worth of lifespan, but it seems like the battle would last longer. My body was screaming in pain as it was doing movements way beyond what it should be capable of.

With every swing of my sword, the space itself got cut. The wolves along the way died before even realizing what attacked them.

I glanced behind me and saw that Ember was already done barricading themselves inside the clone barricade. Igni and Fang were already inside too, which leaves me alone, facing the swarm of wolves, three liches, and an angry Cyclops.

A full minute passed, and the Cyclops was already looming before me. I raised the sword and slashed downward, creating a rift along the ground and taking the right hand of the cyclops along with it.

It growled in pain as it held the bleeding stump on its shoulder, reeling backward a few steps before kneeling. I did one last swing around me, clearing the nearby wolves and creating a wide, open space.

"Phew..."

I blew out the hot breath that I had been holding for who knows how long. I sheathed my sword and held it at waist level, keeping my stance low. I revved up the circulation of energy inside me as I prepared to use another forbidden skill I created.

Arcs of lightning appeared all over my body as the energy in the air got excited. The rocks around me started cracking as the ripples of pressure were released in waves.I think you should take a look at

I closed my eyes and sharpened my perception, extending it forward.

The Cyclops before me...

The three liches that were preparing to launch another spell to attack...

Thousands of demon wolves were scattered all around the place...

The myriads of 6th and 7th stage demons that were locked in a fierce battle against the military...

Then, finally, the three 8th-stage demons that the top attack squad was fighting...

I opened my eyes and saw sparks flying in my view. The scattered energy in the air suddenly converged along the edge of the sword inside the sheath. My legs sank to the rocky ground as I prepared to move.

"Forbidden Technique: Echoing Thunderclap!"

With a short whisper, all the sounds in the surroundings vanished. A single flash went around, following a jagged path as it passed by every single demon that was present.

In the middle of the flash, I was waving my sword in a precalculated path. The demons I passed by turned into nothing as they were destroyed at the molecular level.

The energy at the sword's edge slowly increased as more and more demons fell to it, as if their lives were fueling the sword with more power. With a single touch of the sword, a thousand cuts were released. Nothing remained of even the towering Cyclops that was oh so powerful before.

The energy that the liches gathered for their spell got absorbed and incorporated into the sword's edge. The sword was now blazing with high amounts of energy, creating an illusion as if it were burning with a raging flame as it wisped away the lives of everything it came into contact with.

A hundred, a thousand, two thousand… The monsters around fell one after another. As I reached the area near the military, I only passed by those who were far from an ally. At my speed, it was hard to make minor adjustments to the sword's trajectory, so better safe than sorry.

An instant passed, which felt like an eternity to me. As I returned to my previous location, doing one complete circle around the whole battlefield, I sheathed the sword and dispersed the energy it stored upward.

Time flowed again. A large lightning bolt fell where I stood. My afterimages zipped through the demons, releasing explosions for every action they took. The entire field was smashed not by the monsters but by my steps. Loud noises like thunderclaps echoed from all over the place.

Lightning fell all over as the air got charged with too much energy and had no other way to release it. However, the lightning never hit anyone or anything. The demons... Everything within a few kilometers turned to dust simultaneously.

I undid Lifeblood and smiled in satisfaction. With this much, everyone should already be safe.

As I turned around with difficulty, I could see three girls with tears in their eyes as they rushed to my side. Then, before they even reached me, I lost consciousness.