Originally written for Rihanna’s album ANTi, “Reaper” was later scrapped. Sia talked about the process with Rolling Stone Magazine:

They’ll entice me into a session by saying, “Rihanna will definitely be there” or “Kanye will definitely be there,” but it’s hilarious because I turn up and, almost always, they never come. So I went into the studio to write for Rihanna with Kanye and neither of them showed up and stayed for less than an hour. They had two tracks. They told me what they had wanted. There were notes from Kanye, and I can’t even remember what they were. I remember I just raced in and raced out, and I thought there was something about the chorus that seemed fun about this song.

Sia continued to talk about the track with Rolling Stone, stating she doesn’t have strong feelings for the song:

I don’t care about the song. I know in print that will look bad, but what I mean is I’m not emotionally attached to it. I thought it was a fun song. I think it’s a good, fun song, but I didn’t anticipate it being on the record. But my manager really likes it so I put it on for him.