Backstory:

One of the four Representative Creations, she is the representation of the Creator's madness, she was imprisoned in the Creation Prison by Queen Purpura, for having convinced a Creation to become violent, she says that was not exactly what happened, but due to her manipulative nature few trust her, so she was just trapped.

She is based on a kitsune, she is also able to change shape, copying forms of other characters.

During her fight in the neutral/pacifist route, if hitting the bars of her jail cell, she would break free and possess Rio, causing him to always attack his enemies and giving the option of everything else to Winna.

Speaking of Winna, after Winna is gone after the full genocide route in Purple Kingdom, Madsune convinces Rio to free her, making her be the partner of Rio from there on.

Encounter Text:

[Neutral/Pacifist]

MS: Oh, look at that, new friends.
MS: What do you want? A fight?!
MS: HAHAHAHAHAHA.
MS: I'm behind bars, brown boy and purple girl.
MS: You really want to hit the bars?
MS: Then go for it.

[Genocide (1)]

MS: Hey there, my insane friend.
MS: Who would've guessed we are not so different.
MS: HAHAHAHAHAHA.
MS: Heh, sorry for that.
MS: So, can you free me now?
MS: I magically put the key in your pocket.

[Genocide (2+)]

MS: Couldn't get enough of me, huh?
MS: Then let's go, there is no time to waste.

Check Text:

*Madsune the personification of insanity.
*Something tells me we shouldn't hit the bars.