Y/N becomes a Hashira at the age of 12, 2 months after Muichiro.
Y/N's mother is the voice in Y/N's head.
Y/N had help learning the breathing technique by a voice in their head and their dad
Y/N is a quite bit distant from people
Y/N always seems to have a solemn look on their face.
Breathing Technique: shadow breathing
7 forms (that are known) [+1 y/n made themself]
First form: sunless day
Your blade becomes darker and sharper, which can cut through metal with a hard enough swing.
Second form: lonesome blade
Speed increases by 10%. The blade glows the darkest shade of (favorite color), which makes a small minor burn on a wound.
Third form: Moonless Night
A shadow of the moon appears on the blade, it doesn't do anything two special. Speed of opponent slows down by 40%, when is cut by the blade after this form is used.
Fourth form: dusky sky
The sky seems to darken for a few seconds, which allows a light smog to appear around the area of fighting. Makes it hard to see from a demons point of view
Fifth form: lightless slash
The sword becomes a tiny bit lighter, a cut doesn't seem to make any pain for the demon at all. One slash multiples to 3.
Sixth form: silent wish
All surrounding sounds seem to disappear, which makes it easier to concentrate for a short amount of time. One slash multiplies to 2.
Seventh form: lurking shadows
All shadows near by seem to take a shape like a human and then hold down an opponent, by grabbing the opponent's shadow, for a short amount of time.
Eighth form: midnight reign
Y/N makes a dragon shadow appear where her sword usually does, and an attack on an opponent hurts like hell. A slash burns and feels like a bunch of sharp slashes in one spot.
(Extra info)
Chapters will be shitty, need to refresh my memory.
Updates will be slow.
Sorry if this doesn't make sense.

YOU ARE READING
Whats your name again? (Muichiro x reader)
FanfictieY/N lived with both of her parents until the age of 4. Their demon slayer mother was slaughtered by a demon on a mission. Y/N didn't understand at the time, but their father did. Y/N father began to throw out everything that related to Y/Ns mother...