"They are the specimens from the single Facehugger?" 
"Yes Mr. Weyland, Specimens 1 and 2 have shown remarkable development over the past 3 days, and are improving faster than the other specimens"
"Very good. It seems Specimen 6 isn't the only special one amongst this batch. Get them branded and move them to the testing facility"
"Yes Mr. Weyland" 

The three of them left swiftly, leaving the two xenomorphs, specimen 1 and 2, alone in the room. Following their departure came a piercing screech in their heads. 『Ugh...』 we hissed loudly, staring at each other as a new command was given by the Queen to escape. The sirens were activated and the lights were flashing red all over the base. People screamed and were rushing outside the room the two were staying in. 

BANG!

A loud thud was heard outside the room as a black elongated head could be seen through the dented gap between the doors. A pair of black claws reached inside the gaps forcefully opening the door. The two inside the enclosed room were restless swaying their tails side to side staring at the xenomorph that stood upright. It walked over to the controls and destroyed it with its inner jaw, opening the door to the enclosed room.

We both froze on the spot as something unexpected happened. Along with a certain invisible force passed through the facility, we both got a mental alert saying we need to meet certain requirements to activate the system. But with the commotion going on outside, we pushed it aside and looked at the waiting xenomorph.

The three hissed at each other before immediately running out of the room and meeting up with tens of other xenomorphs. When we turned the corner, a squad of armed soldiers greeted us with a round of bullets. Although they didn't penetrate our hard exoskeletons, they did pack a punch, which only made me annoyed. "Die you fuckers!!!!" A Caucasian man shouted, spraying his rifle in my direction.

I leaped forward taking down the loud soldier firmly holding him down with my claws as I leaned closer to his head. I sliced off the neck of a soldier rushing to help while biting through the skull of the soldier below me. The other xenomorphs didn't hold back either and we quickly took down the whole squad, however, we did lose some xenomorphs. Anxiously turning my head, I found my sister frozen in place a few meters behind. 

『Sister, we are monsters now, it's better to move on with it than to dwell over it constantly』
『You're right... I'm sorry brother, I just thought that we could hold onto what little humanity we had left. I'll listen to you』
『Good. Let's go then』

We were behind now that we had a little talk and caught up with the group, decapitating researchers running out from the rooms ahead of us. It seems they thought the xenomorphs had all passed, but it's unfortunate that we stayed behind. When my sister had killed her first researcher, we both got another alert in our minds. 

[First Requirement achieved. Limited access to the System available.]
'System? What are you?' I asked, biting through the head of an unlucky researcher, throwing his lifeless body to the ground. 
[The System is both an Evolutionary assistant and Rift maker. The names are self-explanatory, in that I will help you evolve more smoothly and with a wider variety of Evolutionary paths as well as open rifts to unknown worlds]
『What are the other requirements to fully unlock the System?』 My sister chimed in appropriately while we stalked 2 soldiers up ahead. We dropped onto them at the same time and pierced our tails through their backs, intestines hanging on the bladed tip that pierced through their stomachs.
[First requirement: Kill and devour a Human 2/2. Second requirement: Kill and devour a hundred Humans 5/100. Acquire a large energy source 0/1.]
We both looked down at the two bodies and crouched over to bite their skull. 5/100 changed to 7/100.
『It seems we share the system. Then, sister, we need to split up to quickly kill the remaining Humans, or there won't be any until the marines show up which I don't know how long would take.』
『Okay.』 She said and took off into an unexplored direction, not so much as questioning her brother 』 words. I also ran through several hallways and crawled through many vents, reaching a cafeteria with tens of surviving researchers and soldiers. 

ML POV

I snuck around in the vents and hid in the shadows, circling the crowded group who barricaded themselves with chairs and tables. I closed in on them and dropped right into the middle of them, frightening the researchers and alerting the soldiers. The 3 soldiers aimed at me but hesitated as there were researchers still beside me.

"Get out of the damn way you idiots or we're all dead!!!" 

Too bad. I had taken that slight hesitation and already decapitated the heads of 3 crawling researchers A B and C, then biting the neck off of researcher D who was scrambling to his feet. The soldier's A B and C opened fire not caring about the safety of the remaining researchers. I avoided several bullets and threw researcher D's dead body to soldier A, then launched my body towards soldier B, ripping the gun from his hands and throwing it away before biting through his skull. 

"Fuck it!! We're all dead so I might as well take you with me asshole!!!" 

Soldier C grabbed a grenade and rushed towards me with despair-filled eyes. I didn't think that one of them would lose their minds and kamikaze! So, leaping as far away from the crazy soldier, less of the explosion hit me but still pushed me several meters through the air, crashing through the barricades and hitting the wall. Luckily, no serious injuries were sustained and only several burn marks across my body appeared. Soldier A and many other researchers were still barely alive, to which I quickly killed them and ate their brains. I left the cafeteria and stalked the halls. Several minutes later I swept through the entire area, killing another 22 people. [43/100]

FL POV

"Quickly!! They're coming, lock the damn doors hurry!" 
"We can't! The command controls been fried, nothings working properly. Fuck, we're dead! Dead!"
"Are you a marine or a coward!!" shouted soldier A
"I-I'm a marine... sir!"
"That's right! Now we defend this area with our lives! Evacuate the researchers and civilians to the emergency escape pod!" While he was shouting orders, soldier B's face became progressively paler as his teeth clattered, looking behind soldier A in horror. Soldier A had a bad feeling but was too late, a bladed tail pierced through soldier A and B, ruthlessly pulling their intestines as blood poured to the floor, coloring the white tiles crimson red. I pulled out my tail and swung it to whip the blood off, pushing aside the two soldiers' bodies and running after the escaping civilians and researchers, mascaraing all of the last survivors of the dormitory. Several minutes later an alert entered my head.