Can I use Geass on demons if I still had it?

The new world

Lelouch was feeling something different, yet nostalgic.
He touched his body with his hands, he, he was now in his 7 year old body.
"c.c.? C.C.?!, Where are you C.C.?!" Lelouch couldn't find C.C. anywhere, he was scared, like a lost child, he scoured everywhere for his dear C.C., until he fainted.

-Time skip brought to you by our dear Nunnally-
"Oh my, dear brother, he seems so lost",Nunnally
"Yeah, poor him" Kallen
"Well anyways, its time for a Britannian Secret!" Shirley
Nunnally says, "Apparently, big brother used to hate his own birthdays, he would act isolated on his birthdays to avoid people..."
"Awww, that's sad. Poor Lelouch", Cornelia says
-Back to the story-

"Wake up"-???
"Who is there?"
"Ahh~~ he's awake"-???
"Who is this boy, papa?"-???
"Tanjiro, he....is our guest"-???
"Ahhh, I see"-Tanjiro
"Japanese.....they are speaking Japanese...is this Japan?"-Lelouch
"Yes dear child, you were in the woods, ring a bell?"-???

"No", Lelouch says, 'Its not like I don't remember, I just couldn't tell them I am from Britannia, and there is no guarantee Britannia even existsi n this Universe if it is another one'

"Looks like you lost your memories, I'm Tanjuro, Kamado Tanjuro, this is my wife Kamado Kie, and my son Kamado Tanjiro, and there is our daughter Kamado Nezuko out for gathering Fruits and vegetables, there's Takeo, Hanako, and Rokuta"-Tanjuro
"I see, well then I will be in your care until I recover my memories, thank you"- Lelouch

*3 years later*


"Oh hey Nezuko!"
"Ahh, Lelouch!"
"So, how many fruits and berries you got"
"Many!!"
"Well, I'm going to the village with Tanjiro to sell coal..."
"But I don't see Tanjiro"
"Well he is coming, he must be describing Takeo that he cannot come with us right now"
"Ah I see~"
"Lelouch! Nezuko!~"
"Ah, there is he, HEY TANJIROOO!!"
"Haah-Haah *pants*"
"You were late Tanjiro,"
"I know, lets go"
"Tanjiro, Lelouch..."
"Yes Nezuko?" Tanjiro and Lelouch said in Unison
"Take care,"
"Yes, we will, right Tanjiro?"
"Ah yeah"
"Bye!"
"BYEE!"

Well, our small 10 y/o Lelouch was no longer skinny, he was strong, he could protect them, maybe. He always trained with the sword with Tanjuro, he learnt the correct Breathing technique, even though he hadn't mastered it yet, he even got a Katana on his 8th birthday from Tanjuro, he has it as a keepsake for Tanjuro's memory, he still hadn't found C.C. yet though...

Currently, they were going from one house to another separately to sell coal, on their way back to home, it was really dark, thus they were stopped by a kind old man to stay there.

"You kids shouldn't go out at night, there are demons lurking"

"Demons~" the word gave Lelouch shivers, which reminded him of his time as Demon Emperor

"Demons eat people, they are ferocious"
"It's fine, I could protect myself"
"But Lelouch"
"Tanjiro, you could stay here, I have the responsibility to protect them"
"It's my responsibility too!'
"Stay here, you are weak"
"Alright! Alright! Don't come crying to me if you see a demon!"
"yeah I wouldn't!!" Lelouch rans in the direction to home

"Quite a stubborn child isn't he?"
"Lelouch has always been like that"

As Lelouch was running towards home, he felt a strange feeling in his chest.
"what is this feeling, it feels like something-I-I smell blood"
Lelouch runs as fast as he can, he has to protect them.
"AAAAA!!!"
"It's Nezuko's voice! NEZUKOOO!!!"
"Another one I see"

Lelouch saw Nezuko held by the neck by a man, his family, slaughtered.

"Lelouch! RUN AWAY!! AGHHH!!"
"NEZUKOOO!'
"Shut up insect!"
"Youuu! sssssssss-*breathing noises*, Hinokami Kagura!"

Lelouch unsheathed his Katana gifted by Tanjuro, and lunged forward at the man, his blade in flames of the sun,

"WALTZ!!"

"Annoying"