Board Thread:General Discussion/@comment-6192846-20130812010713/@comment-6192846-20140618225204

First off:

Lyric-wise, and story-wise, the *** Whisper is most likely the "HER" Whisper. Both have their lyrics written in mostly katakana I hate you mothy while the HER Whisper is done in Kanji.

So the indication would imply it was: HER --> Possibly Real Elluka --> HER again

As for that lyric? Unfortunately, I can't translate katakana that well I hate you mothy so I can't confirm or deny what the fan subs say (though never trust what fan subs say).

That said, I don't see any use of 罪 (tsumi) used there, and I don't see another term that would mean "sin" there. I'll edit this post if I can find out more  from others, but I don't think the line means what you think it means.