Hello Luna! 
You’re very welcome. I do try, as I want to actually be helpful. 
That’s absolutely fine, I understand. I’m a native English speaker and I have no problem proofing others’ work, but REALLY struggle with my own. I can read mine over ten times and still miss some. It’s because we know our work and read it the way it should rather than the way it is.
That’s all good, I’m diving into it now! 
Here you go, my corrections are in bold.
For Chapter One:
Narrator: “…that would bring you immense power over your…”
Power list:
- Being able to control people physically
- Being able to make people think exactly…
- Being able to be invisible
- Being able to read other people’s mind
Narrator: “…all had some sort of magical ability…”
Alina: “Oh god, Michael, I can’t take this…” - add commas
Alina: “I’ve got this terrible, terrible feeling in my gut, and I…”
Alina: “The one that you became such good friends with.”
Alina: “Please come back to me, brother…” - add a comma
Alina: “Oh my god, it is you!” - add a comma
Alina: “You’re so cold, Michael” - add a comma
An “under detective” isn’t really a thing, maybe just call him a detective while the other is superior detective?
Superior Detective: “Well, you sure took your time…” - add a comma
Under Detective: “Considering the blood splatter, …” “Considering the splatter of the blood, …”
Under Detective: “…one of the nicest people they had known.”
Superior Detective: “He killed himself afterwards since she had ruined…” - no comma
Under Detective: “Please forgive me, sir.” - add a comma
Leon: “…makes all the jerks GET high positions.”
Leon: “Scaredy-cat” as “Scaredy-boy” isn’t a thing.
Leon: “It is as the other man said, none of this…” - add a comma and ‘man’ is better than ‘guy’ for the time period. Also, the teddy comment seemed a little too immature for the time period and age of the character.
Leon: “Communicating with animals, was it?” - add a comma
Leon: “…breaking into my house and eating all my food.”
Leon: “I’m sorry, Michael, after hearing what a good…” - add commas
Leon: “I’m going to take you, and your poor sister, back to The Order, so Namira…” - add commas
Leon: “This probably won’t be any comfort, but…”
Namira: “You two seem inseparable.”
Diamond: “…fun together, and I am happy he is my co-agent…” - add another comma
Namira: “It wouldn’t be so funny and lively around here without you two.”
Diamond: “…little things that annoy me.”
Diamond: “He has real trouble with being serious…”
Diamond: You JUST made an agreement with…"
Diamond: “…over the floor? Do you recall any of that?”
Namira: “I guess I’m just easily scared.”
Namira: “By the way, why do you always call Diamond, Zua instead?”
Namira: “Well, thank you, Diamond!” - add another comma
Namira: “I guess I can get lonely in here sometimes, working so many” - move the comma
Background: Little Leon’s Lessons
Leon: “…that are against our King’s imperialistic policy.”
Leon: “…about these types of things.”
Leon: “Namira’s power is that she can… …when you’re a mechanic and scientist.”
Leon: “…like only our leader knows why she’s really here though.”
Leon: “…sneak into the men’s showers…”
Leon: “You’re not old enough for…”
Diamond: “…come up with such an idea, Leon, honestly.” - add another comma
Leon: “I’m the Black Order’s second agent, after Diamond.”
Leon: “…them to you as you meet them through…”
Leon: “Now that I have introduced us.”
Leon: “That was all for ‘LLL’ this time.”** or “That was all for Little Leon’s Lessons this time.”
ALSO, you’re love triangle only has two sides and triangle have three.
Leon: “I’ll see you in the next episode!”
End of ‘LLL’ - This would actually make a really good place to end the first chapter, then continue in episode two.
Namira: “And I dare say that it is…”
Namira: “Somebody had ripped out his heart and…”
Namira: “I could not pull my head around…”
Namira: “There are times like this that makes…”
Leon: “Why? What was wrong with the machine heart?”
Namira: “…that I realized his body was still working, …”
Namira: “Did you not pay attention to…” - you don’t need to say literally
Namira: “In other words, his body became like an empty…”
Namira: “And I still have no idea why…”
Narrator: “The Empire built up their invincible navy after the known…”
Narrator: “…hunger for power continued to grow each day.”
Narrator: “The upper-class were getting used to…”
Narrator: “A country known for their greatness in culture, and science and technology for thousands of years.”
Narrator: “…precious tea, silk, and porcelain…” - add another comma
Narrator: “This plan was, obviously, not accepted…”
Narrator: “…other countries ceased to exist.”
Narrator: “But before anything…” - what? Don’t you mean… “But before we continue.”
End of backstory - This would also make a really good place to end the chapter, then continue the character intro in the next episode.
Isabelle: “And I can read people’s minds.”
Isabelle: “We look slightly similar, yet our looks are…”
Isabelle: “…customize us at the end of the episode.”
Explaining that both names end in ‘belle’ isn’t needed, it’s obvious, and only makes you seem like you think your audience is stupid.
Isabelle: “… left Annabelle and I in front of Maywood…”
Isabelle: “… left us in the best orphanage…”
Isabelle: “Our amazing aunt Jane.”
Thomas: “Beware, small girls.” - add a comma
Thomas: “…pirate by the name of Mac-”
Narrator: "…Mac Super Evil’s threat about…
Isabelle: “But pirates don’t eat humans, silly!” - add a comma
Thomas: “…going to take you as mytreasure!”
Isabelle: “The evil pirate, Mac Super Evil, is coming to take us” - add commas. Also, ‘take’ because I chose that pirates don’t eat people.
Isabelle: “Now is the time, Aunty!” - add a comma
Choice: You were so brave to be the pirate.
Thomas: “I don’t think I was that”
Isabelle: “Annabelle, Thomas and I were often inseparable.”
Isabelle: “…have passed, still to this day.”
Matthew: “You’re in, Aunty!”
Aunt Jane: “I’ll take that challenge, so…” - add a comma.
Isabelle: “…that only seemed to worsen over time.”
Isabelle: “…not a single one managed to figure out what it was.” or “…not a single one could figure out what it was.”
Annabelle: “Me too. I always miss you.”
Isabelle: “Over the next few years, children came and gone, as…”
Isabelle: “…comes to Annabelle and I…”
Isabelle: “…made us promise not to say anything…”
Isabelle: “…clothes using a sewing machine.”
Customer: “Hello, dear Belles.” - add a comma.
Isabelle: “My expertise in medicine often attracted…”
Narrator: “…takes place in our present day.”
Miss Darbeyshire: “He eats young girls’ hearts.”
Miss Darbeyshire: “Now, my dear, what do you…” - add another comma
Elisabeth: “…actually is an angel, you know?” - add a comma
Miss Darbeyshire: “It would surprise me if she was.” - no comma
Miss Darbeyshire: “Let the bill be on me, Elisabeth.” - add a comma
Elisabeth: “Thank you so much, Miss Darbeyshire.” - add a comma
Miss Darbeyshire: “Maybe Annabelle might have the time…”
Johnathan: “Thank you for the address, ladies.” - add a comma
Sorry, I made it inside the shop, and couldn’t continue. The first part was so good, but it was far too long, a little monotonous, and choices were few and far between.
I loved the intro and splashes, though the very first one moved a little too quickly. You may want to prolong it by a second longer. Also, you don’t NEED to put an ellipsis (…) after every line. Periods/fullstops/comma would work better for what you’re trying to achieve. I would honestly remove MOST of them. 
Also, during the Little Leon’s Lessons, a couple of the background/overlays were shown early (for a second) and I wasn’t tapping too fast. If anything, rather slowly.
You should really cut this chapter down because as much as the story is good, I was really struggling to get through this because of length.
Your story started off so well, but from the point where we were introduced to the sisters, it became tiresome. It seemed to get slower and full with details that aren’t really necessary.
If you cut it down and tweak it then I’m happy to reread/keep reading, BUT it’s far too long for an Episode story. If you want to keep the length, then I suggest moving it to Wattpad instead.
Hope this helps,
Caliope-Checker
)
it’s very helpful and I will improve it 
Thank you, Caliope.