Board Thread:Theories Discussion/@comment-3264064-20130412103240/@comment-5320504-20130412115142

The song itself is not actually talking about the hellish yard or anything to do with the events occuring in evillious, rather the song is based off Yukina Freesis' book of the same name. Ma composed it from that book and the Master of the Court intends for it to be sung as the theater occupants got to collect the last vessel in the underworld, as in "marching to the end".

It just fits because the "criminals" are alot like the theater occupants in that they are sinners, but as for the actual end we can't be sure the Master of the Hellish yard can even do anything to the other vessels as most aren't human and that in all technicality she is likely just like them. But the possibility does exist that it could instead refer to whatever end occuring as punishment to them. We still need alot more before we can really be 100% on anything, but this is based on what is canon so far, I hope it is fine by me saying this.