Past sins was such an inspiring story. It warmed my heart with joy when Twilight saw Nyx as her Daughter, broke my heart when Celestia took Nyx away from twilight, and warmed my heart again when Nyx returned to normal and became Twilight's adoptive daughter. I haven't been this choked up ever since I first saw My Little Dashie. Every story and idea people make really opens my heart to love, joy and Happiness.

To all the folks asking,

Nyx... aw, Nyx is awesome.

Nyx is a greek god. She is the goddess of the night.

Nyx is a character from the fanfiction Past Sins by Penstroke. Some ponies tried to resurrect Nightmare Moon but messed up the spell and Nyx was created. Twilight adopted her at first just to keep an eye on here but then grew to love her like a daughter.  Reality Check also wrote some stories that use her after the events of Past Sins as does Penstroke they are all good reads.

This was so cute I almost cried!

Twilight must love nyx Because she was tacking care of her.️ This is so sweet.

Aw I love You Nyx and so does Twilight! -LunarEclipse

I am crying right now even when I have read the book past sins

this song made me cry.....

so beautiful!! who ever made this had to cry

This song making me cry so hard now I miss my mom

For those who want more Nyx, although probably not quite the same as the Past Sins version (although pulled from there), the MLP Time Loops "story" on FiMFiction has her there, too... has a bunch of other things, but the mini Nightmare who learned her own way does show up part way through.