What if Saitama has a biological sister?

Black Matter Thieves v.s The Siblings

*Inside the Spaceship*

Groribas was seen standing at the wall support and confronted the siblings.

Groribas: "kekek~ you dare infiltrate our ship!? Me, Groribas, one of the general will defeat you! I'm gonna use my acid to melt you two to death---"

Nancy speedblitzes by punching Groribas' head and killed him off.

Nancy: "ewww, the acid stained my pajamas...." *Her pajamas was damaged from acid*

Saitama: "let's split for now, this ship is super big that I am about to get bored finding the other aliens"

Nancy: "I agree-- no wait a minute, we must walk together you idiot!" *Pinches Saitama's ear*

Saitama: "hey, ouch!"

Nancy: "we must fight together! Or else you'll get lost!"

Saitama: "fine"

Nancy and Saitama walks but some alien used telepathy

Geryuganshoop: "intruders! Earthlings or whatever you are! You must exit our ship or else we will bring our strong armies to assassinate you there!"

Saitama: "someone just speak in my mind, did you do it?"

Nancy: "eh? I'm not"

Geryuganshoop: "intruders! Last warning! Get out in our ship or face consequences!"

Saitama: *shouts* "even if we wanted, we don't know the directions!"

Geryuganshoop: *smiles in curiosity* "really!? You two are going to go out!?"

Nancy: "yeah so where is it?"

Saitama: "hey I asked the question first! Let me handle it"

Geryuganshoop: "okay, listen! Take right and go upstairs, go straight until you see the light there, that's the exit"

Nancy: "take right?"

Saitama: "right direction...."

Geryuganshoop: "yes!! Right direction!"

Nancy: *evil playful smile* "hey big bro, do you know what I am thinking?"

Saitama: *evil playful smile* "yes yes yes~ let's go to the left side hehehehehe~"

Nancy and Saitama goes to the left side instead of right side

Geryuganshoop panicked.

Geryuganshoop: "no wait! Wait! Why are you going in left direction!? It's a wrong direction!"

Nancy: "it's obvious, we are going to beat you guys up for destroying our city"

Saitama: "damn right"

Geryuganshoop: "aaahhh! No wait! Just stay there! Don't come here! Nooooo!!!"

Nancy and Saitama punches the door leading to the control room

The alien subordinates were shock and goes alert

Saitama: "this looks like control room

Nancy: "isn't that obvious!?" *Gives Saitama a cheek pinch"

But someone slither out in the corner.

Geryuganshoop: "Oi!"

Nancy: *being nonchalant* "yeah what? Tryna scare us! You takoyaki alien"