Been thinking about all of this far too much. Which it seems is the goal. "We will get inside your head, one way or another." - An old quote referring to the reasoning behind the Merciful Release logo using the anatomical guide to peeling away at a human head.
Then there is the name of the band. Now, 'sisters' are a type of sibling. When it comes to Von's love of philology, one could wonder if the siblings of 'mercy' itself are what are really being referred to here.
In which case, the first think that comes to mind speaking philologically that would by a sibling of a term/word, would be synonyms and antonyms. Let's take a look:
http://thesaurus.reference.com/browse/mercy
Now for brevity let's only use that one reference.
Main Entry: mercy
Part of Speech: noun
Definition: kindness, compassion
Synonyms:
benevolence, benignancy, blessing, boon, charity, clemency, commiseration, favor, forbearance, forgiveness, generosity, gentleness, godsend, goodwill, grace, humanity, kindliness, lenience, leniency, lenity, lifesaver, luck, mildness, pity, quarter, relief, ruth, softheartedness, sympathy, tenderness, tolerance
Antonyms:
cruelty, intolerance, meanness, uncompassion
I guess what I'm getting at here is that perhaps the antonyms are more likely being referred to over the synonyms.
"You are very bad people and must be punished"
- On Stage Comment
From the inlay to the 2006 re-issue of Vision Thing:
"Asked by Chris Roberts in Melody Maker in 1990, whether he was giving fans of The Sisters Of Mercy what they wanted, Andrew Eldritch replied: "Oh, I hadn't really thought about that. I've always taken the view that what I want to give them is what they need. What they want is neither here nor there. I know what's best."
Perhaps all it's ever been is a series a well crafted psychological games.
See also:
http://en.wikipedia.org/wiki/Psychological_manipulation
Especially:
Quote:
"Basic manipulative strategy of a psychopath
According to Hare and Babiak[4], psychopaths are always on the lookout for individuals to scam or swindle. The psychopathic approach includes three phases:
1: Assessment phase
Some psychopaths are opportunistic, aggressive predators who will take advantage of almost anyone they meet, while others are more patient, waiting for the perfect, innocent victim to cross their path. In each case, the psychopath is constantly sizing up the potential usefulness of an individual as a source of money, power, sex or influence. Some psychopaths enjoy a challenge while others prey on people who are vulnerable. During the assessment phase, the psychopath is able to determine a potential victim’s weak points and will use those weak points to seduce.
2: Manipulation phase
Once the psychopath has identified a victim, the manipulation phase begins. During the manipulation phase, a psychopath may create a persona or mask, specifically designed to ‘work’ for his or her target. A psychopath will lie to gain the trust of their victim. A psychopath’s lack of empathy and guilt allows them to lie with ease - they don’t see the value of telling the truth unless it will help get them what they want.
As interaction with the victim proceeds, the psychopath carefully assesses the victim's persona. The victim's persona gives the psychopath a picture of the traits and characteristics valued in the victim. The victim's persona may also reveal, to an astute observer, insecurities or weaknesses the victim wishes to minimize or hide from view. As an ardent student of human behavior, the psychopath will then gently test the inner strengths and needs that are part of the victim's private self and eventually build a personal relationship with the victim.
The persona of the psychopath - the “personality� the victim is bonding with - does not really exist. It was built on lies, carefully woven together to entrap the victim. It is a mask, one of many, custom-made by the psychopath to fit the victim's particular psychological needs and expectations. The victimization is predatory in nature; it often leads to severe financial, physical or emotional harm for the individual. Healthy, real relationships are built on mutual respect and trust; they are based on sharing honest thoughts and feelings. The mistaken belief that the psychopathic bond has any of these characteristics is the reason it is so successful.
3: Abandonment phase
The abandonment phase begins when the psychopath decides that their victim is no longer useful. They abandon their victim and move on to someone else. In the case of romantic relationships, a psychopath will usually seal a relationship with their next target before abandoning their current victim. Abandonment can happen quickly and can occur without the current victim knowing that the psychopath was looking for someone new. There will be no apologies for the hurt and pain they cause because psychopaths do not appreciate these emotions."
An interesting phrase that comes up time and again when researching psychopaths is "victim of circumstance", a mode they like to play with to garner sympathy.
Then of course there are the different phases the albums represent.
First and Last and Always: "Playing the victim"
Floodland: Introspective, yet entirely obsessed with sex, war and drugs.
Vision Thing: Elements of above yet now the full ego is in control, the victimization played previously reduced to "learning to cry for fun and profit", or "crocodile tears" another aspect of a psychopath.
In UTR #14, when discussing the lyrics of "Vision Thing" in response to a fan that objected to his use of the vernacular phrase "mother f**ker", he defended his usage by delving into and exposing the different perspectives that are represented in the structure of the lyrics. That there is a separate (or seemingly-so) narrator and author, and that they do not necessarily agree. Yet this use of masks and veiled structures to hide ones true intent or self is also a relevant technique.
This is most noticeable in the lyrics to a song like "Ribbons".
Then there have been other direct references to psychopathy in seemingly-barely related works by artists that should have little or nothing to do with the Sisters per se, any longer yet may or may not have had a serious link in the past.
To be "Without Conscience" is also a primary trait involved here for instance.
"Psychodalek" ( By: James Rays Gangwar) seems to be a play on all of these themes merely exposed in a more direct manner.
"Psychocult" (By: The Merry Thoughts) while lyrically relates to a group of people, "In the suburbs/in the towns/A psychozone/Where the saints/the unbelievers/found a home/And the love we give/Is more than you could bear/And the fever/And the fever/And the heat are there." It still firmly establishes the same sentiment that one party is give "love" that is more than the other party involved "could bear".
Although it could be argued that whether supposedly directly unrelated to the Sisters or not, the lyrics to "Psychocult" are pointing at us as a fan-base in particular.
Another possibility previously mentioned elsewhere on the forum, is Amphetamine Psychosis:
http://en.wikipedia.org/wiki/Amphetamine_psychosis
Although, one starts to wonder exactly how much of every activity mentioned in interviews in the past attributed to oneself were merely attempts at sounding cool, or explaining one's behavior with drugs and their effects rather than some other explanation.
The final possibility is that a cunning goal was to prove that people are naturally interested in psychopaths and that it would be an interesting literary device to write lyrics from that point of view and to portray oneself in that light to help the "suspension of disbelief" only seldom "breaking the fourth wall" and exposing one's true self through the lyrics or interviews when necessary shock value, as discussed in UTR#14, ask for it.
The Fourth Wall:
http://en.wikipedia.org/wiki/The_fourth_wall
Maybe has something to do with the "Fourth Floor", another early play on words, perhaps.
All in all, very intriguing, which doesn't detract from A.E. being a very interesting singer/songwriter.
As to who he really is and what he's really all about, I think it's fair to say that he never wants any of us to know or to understand, in any conscious sort of way.
How about focussing on the synonyms of 'Mercy', for a change?
Are you Von's neighbour?
... however, even when you locate 
godzillions, or maybe more, and they'll buy original cd too.
's while ?