Death Waltz is the common misconception for the black MIDI version of COOL&CREATE's U.N. Owen was Her? remix, Last Brutal Sister Flandre Scarlet. A lot of people nowadays still call the song 'The Death Waltz by John Stump,' and TheTrustedComputer posted a video of the real John Stump Death Waltz on his channel to get rid of any doubts.
It is said that a YouTube user posted a video named "john stump - death waltz", even though the song was the very first Black MIDI of LBSFS. It is said that this is how black MIDI reached Youtube.