The Protagonist’s Sister Is Actually The Strongest [An Action-Packed LitRPG Transmigration and Progression Fantasy]

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From all of Baihe’s attacks, she only landed two of them. A piercing blow on my left shoulder and a small icicle that attempted to pierce my right leg but failed to do so. The cloud of shadows moved there and simply forced the icicle to move out of the way. It was quite incredible how it worked. And that wasn’t even explained in the skill description. I knew I had to try things out instead of just trusting what a skill says it can do.

“Let’s see…!”

I swiftly imbued demonic energy into my claws and caught Baihe off-guard after she released her spell. I swiftly appeared behind her and unleashed a single attack towards her back. An armor of frost materialized over her body in that second, but it swiftly shattered once I hit her.

CRAAASH!

The armor shattered, and Baihe was sent flying into the ceiling. I had not missed that attack, at long last. And not only that, but the hit was also critical, with triple the damage! I saw Baihe swiftly fall to the ground after balancing herself in midair, gasping for air and groaning.

“Hahh… Not yet… I have to keep training this body of mine!” She roared.

“Well said! Relying on your magic alone won’t bring you as far as I want to take you.” I nodded. “Let’s keep it up!”

We continued our clash. Baihe’s attacks continued to become more precise, her magic and her physical blows melding together rather well. I was able to avoid most of her blows, but whenever they connected, I felt like half my body would freeze and become paralyzed. It was a terrible sensation that only lasted a split second, but it was enough to throw off most people.

I kept it up with my claws and kicks, and slowly I began to also use my tail. Using these three limbs, I was more or less able to compensate for my low hit rate by unleashing many attacks at once. Eventually, a few out of the five would often hit, becoming powerful critical hits.

Baihe held off using the recovering accessories she bought using her money from Hilda, who gave her a discount, and also with her newly learned healing magic spells that fit her element. She was getting better at conjuring shields and armor around her body to mitigate damage, too.

“How much until the next transformation?!” Baihe asked, her aura overflowing the entire training room in the underground. My brother had let us train in here for today.

“A bit more; let’s keep it up!” I said, swiftly leaping off the ground and then doing something I have been thinking about. “How about this?”

I controlled the clouds of shadows covering my body and concentrated them all into my claws, like a huge sphere of black clouds. I swiftly threw this smokescreen in front of Baihe’s face, completely nullifying her sense of direction and her vision temporarily.

POOF!

“W-Wha…?! What the hell?”

As she complained while being trapped in the shadows, I struck. I swung my tails and slammed her down, followed by several kicks, which were all mostly evaded by her reflexes and heightened mana senses, but a few connected, striking her armor into pieces.

CRAASH!

“Not bad; I didn’t know you had that trick!” She giggled. “That was not a normal smokescreen!”

However, she swiftly released a wave of freezing mana, blowing me away before I could evade and launching me to the other side of the room. I collapsed and slightly shattered the super-reinforced walls.

BAAM!

“Oh sh*t, Anna, are you okay?” Baihe slightly got worried about me, but that wasn’t necessary.

A cocoon of darkness swiftly encompassed me. This time, it had fleshy tendrils and red veins spreading around my body, slowly mutating me and transforming my appearance into something else.

“Woah…”

As I heard Baihe’s surprise, the cocoon broke and disappeared into particles of darkness, leaving the new me behind. I had the same enhanced height as before, but my body was now completely covered in crimson armor, from head to toe.

[Your Health has reached below 50%, you have transformed into the [Aberrant Flesh Knight of Despair]: Increases Health, Strength, and Vitality by +300%, decreases Agility and Dexterity by -50%. All your Attacks deal no damage to your foe’s Health, but instead deals damage to their Mana, or other energy sources with each hit. Any successful hit has a 30% chance to inflict [Endless Despair] on any foe. Duration: 10 Minutes.]

I became much tougher and heavier, but at the same time, it felt like I was slower. This knightly form was quite aberrant, too. I discovered all the crimson armor was hardened red flesh and bones. And there were many holes across my body where I felt the cold wind that Baihe generated pass through.

“T-This is a bit freaky…” I gasped, looking at my own armored claws. “Anyways, let’s try this one too.”

“Alright! At least it is not as creepy as the previous one…” Baihe gulped saliva. “I’m coming then!”

FLASH!

Baihe appeared before me in a second. I was unable to evade her incoming attack, but I didn’t intend to. I swiftly reinforced my body by using Holy Nether Essence to see how tough I could become, a new ability of my specialization.

Her barrage of piercing spear blows came accompanied by giant blades of ice, but most of her blows simply rebounded off my armor, which shone with a holy and dark aura, as if I were covered by an additional armor made of eclipsing light.

“W-What, no damage?!”

“It looks like this is a pretty good tank transformation. Alright, my turn!”

I wasn’t wearing any weapons for now, so I attacked with my fists, punching Baihe in the stomach. The force of the blow was still there. Baihe was swiftly thrown away several meters from her former position, but her armor of ice didn’t break.

BAAM!

“Huh? That didn’t hurt that much- Ugh?!”

However, she quickly felt it; a decent chunk of her Mana was gone. She directed her azure eyes toward me, widening them. She realized I could not damage her, but each of my blows would drain away her Mana.

“You drained my mana but didn’t deal any damage?!” She asked.

“Yep, this is the transformation’s ability.” I laughed. “It feels useless at first glance, but emptying someone’s Mana reserves can be really useful. Suddenly, they lose the fuel for ninety-nine percent of their abilities; doesn’t it sound terrifying, especially when you can suffer a backlash by emptying your Mana in one fell swoop?”

“T-That’s…!” Baihe stepped back as she saw me running towards her.

“Now I hope you try to evade my blows!” I giggled while swinging my giant, armored claws. Waves of crimson energy were released constantly, exploding into mana-absorbing explosions.

“Shit, shit, shit!”

Baihe looked rather worried, and as we kept fighting, her Mana reserves constantly went down bit by bit. I was enjoying this, to be honest. If I can synchronize this transformation well, I could probably deplete a foe’s Mana completely and then slam them down with a barrage of magic attacks.

Because although all my physical attacks and aura attacks can only deal damage to Mana, my magic can still deal normal damage! I fired the simplest of spells for now to not tire Baihe too much—just a barrage of a few hundred blades of light.

BOOM! BOOM! BOOM!

“Uwaaagh!”

However, she looked quite worried. Maybe I was going so easy on her; she thinks this is threatening now? That’s no good. As my friend, I don’t have to hold back! It’ll be a bit rough, but I’ll teach her to evade these blows.

“Come on, we’re just starting, Baiheeee~”

As I chased her like some horror movie monster, Baihe gave little screams while evading a storm of blows. Her magic was the only thing that affected me, but her physical blows were already not doing much. Also, I think her screams were partially because of the [Endless Despair] status effect, which was healed after a second or two of taking effect.

“Hahh, my head and my body are so exhausted…” Baihe gasped for air, pointing her hands at me. “A-Anna, don’t get carried away; this is just training!”

“I know, and because of that, I won’t hold back!” I leaped into the air and descended towards her with a loud bang. I materialized a sword made of Holy Nether Essence, which I called Blight Blade, and swung it against her several times.

A dozen waves of black light were unleashed, exploding into pure darkness and light. Baihe conjured her shields of ice to protect herself while preparing a strong spell with her remaining mana.

“T-Take this!”

A giant frozen spear was fired at me at lightning speed. I swiftly used my Blight Blade to parry it, but the spell broke instantly! Next thing I knew, my entire left arm, shoulders, and half my torso were gone, the wounds covered by frost.

“A-Anna?!”

Baihe panicked, running towards me. She was about to cry before she saw a cocoon encompassing my body again. She swiftly stepped back. I could now even hear her heartbeat; it was becoming faster. My entire body felt like it slowly melted and turned into air itself. My senses heightened to unprecedented levels; it was as if they were spread everywhere.

Once the cocoon dissipated, I was nothing but a strange, gaseous monster. With giant gaseous claws and what seemed to be a very long head, I had eyes all over my black and dark red body and gaseous tentacles sticking out from below.

My Demonic Energy skyrocketed like never before, and I felt like I was reborn… Even though my HP was now dangerously low, I also felt like I had no longer had energy, but I didn’t feel tired because of that. I had no Mana or Ki at all, but without a physical body, there was nothing to worry about.

So this is the third and last transformation.

[Your Health has reached below 10%, you have transformed into the [False Demon King: The Selfish Manipulator]: Increases All Stats by +400%, but your MP and Ki are completely drained to zero. You cannot take damage from physical attacks. When you touch a foe, you drain 1% of their Mana and Ki per second. When you are hit with a physical attack, you can copy it and unleash it once against the foe with only 50% of their original power. You can manipulate those that submit to you through [Threads of Selfish Manipulation] to make them move as perfectly as you wish. Duration: 5 Minutes.]

Are those threads the tentacles I gained? Yikes, that’s a bit disgusting. And… It looks like I am immune to physical blows! Amazing. It only lasts five minutes, though, so I better make it worth it. Baihe was ready, she finished drinking a Health and Mana Potion.

“Anna? Are you still there?” She asked worriedly.

“Of course. This is just the last transformation.” I giggled; I felt like a giant jaw smiled when I did. “A bit creepy, I have to admit it. Alright, let’s begin. Attack me with your strongest physical blow!”

“Huh, alright! I won’t hold back then!” She roared. “You’re just as much of a monster as I am, if not worse!”

Baihe laughed as she summoned a giant frozen spear and frost armor over her body. In a split second, she appeared above me, her spear unleashing a barrage of powerful attacks against me. However, Baihe quickly realized there was no substance; she was just hitting a cloud of gaseous components.

“W-Wha…?!”

“Physical attacks immunity~”

As I giggled creepily, my body suddenly absorbed the power from her attacks and imitated it. Spears made of red ice emerged out of my gaseous physique and attacked Baihe, striking her armor constantly and covering her protection with countless cracks, until it shattered.

“Ugh! What the hell was that?!” She swiftly stepped back, looking at me in disbelief.

“Counter.” Without hesitating, I flew towards her, extending my gaseous body into gigantic claws and unleashing a barrage of blows.

Baihe had a hard time keeping up with me anymore. I was completely overwhelming her. Not even her magic attacks did much against me either, due to how ridiculously high my stats grew. I simply reflected any physical blow and tanked any magic attack from her.

She was only able to reduce my health to about 7% before the transformation finally ended. And because I constantly attacked her, her energies were also drained almost fully again. The two of us collapsed on the floor, exhausted beyond belief.

“Oof… That was tough…” Baihe sighed. “Y-You’re really a damn monster, Anna! How did you get that skill?”

“It was part of the rewards from defeating Heisenberg… At first, I thought it was a lame skill, but it’s really strong.” I nodded. “Hahaha, and super creepy, right?”

“Yeaaah, you really scared me there. But to be honest, you were still cuter than whatever my stepfather turned into back then, remember? He was just an ugly monstrosity… Hahaha!” She laughed. “You’re cute in comparison.” I was surprised she talked about that so casually. I don’t know if I had to worry about her or be happy that she moved on.

“Y-Yeah, I guess?” I laughed. “A-Anyways, well done! You were pretty amazing yourself. You’ve grown strong, Baihe. But how do you feel?”

“Hahhh… I feel like eating a pile of a dozen pork dumplings right now…” She sighed. “I miss my mom’s dumplings so much.”

“Then let’s order some Chinese food!” I said, quickly standing up and helping her stand up. “Let’s go take a shower first, and then let’s pig out for the rest of the day!”

“Hahaha, okay! Sure! I’m in!” She looked super happy.

Baihe has gone through so many horrible things, and I feel like it’s my duty to always make her feel welcomed and happy. Also, it's necessary to keep her busy so she doesn’t think about depressing stuff.

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