Using the theories of the Swiss psychologist Carl Jung, the people in this dream are almost certainly archetypes from the collective unconscious.

The female friend might be a symbol of the shadow.  The shadow is always the same sex as the dreamer.  In men, he is always male; in women, female.  The shadow is, in some way, the opposite of the dreamer.  There are basically two types of shadows ? the negative shadow and the more positive shadow.  (If she is not the shadow than the blond wife might be.)

Almost everyone has a negative shadow.  The negative shadow is someone who has those negative traits that the dreamer wants to hide from herself and probably from others as well.  At his best, the negative shadow has some minor problems such as poor taste in clothing.  At his worst, he is a vicious, selfish killer who attacks the other archetypes.  (BTW -- it is amazing how many ?good? people have negative shadows.  It is though these people are suppressing their shadows.)

The more positive shadow is the opposite of a person in the sense that he has those positive traits that lie dormant within the dreamer. 

Jayceon Terrel Taylor would be a symbol of the animus.  Using the theories of Carl Jung, the animus is an archetype from the collective unconscious.  The animus is always male and is only found in the dreams (and psyche) of women.  (The anima is the female equivalent and is only found in men.)  During the course of many dreams, the animus can potentially go through four stages of development.

1.   Stage 1 -- The animus is the physical man.  At his best, he is the muscular hero who saves the maiden in distress.  At his worst, he is a materialistic brute who is only interested in his own self-gratification.
2.   Stage 2 -- At this stage, the animus is either the romantic lover or the man of action.
3.   Stage 3 -- At the third stage, he is a man with a message.  Common symbols for the animus at this stage would be a politician, a preacher or a professor.
4.   Stage 4 -- At the fourth and final stage, the animus becomes a spiritual guide for the dreamer.  Although he is a guide, he may not always be a religious figure.  The animus could appear as a wide range of different men.  This would include (but not limited to) the Dalia Lama or Carl Jung.  And, I believe that the animus at this stage will sometimes show himself as mythological or pagan deity.  Examples would be Odin or Loki who would most commonly show themselves in the dreams of women with northern European ancestry.

Her animus appears to be at the first stage of development.  However, trying to determine the stage can be a little tricky and is not always obvious.

There is also a couple in the dream -- a husband and wife.  Who are they?  I can think of a couple of possibilities:
1.   This dream pair is seen in the myths, stories and religions of different cultures.  They are called the Royal Couple, the Divine Union, the Sacred Marriage and such.  The psychologist calls them syzygy.  It is the joining of opposites.
2.   Another possibility is that she is the fourth personification of the four ego functions.  She may be your shadow.  (See below.)  Her husband might be another version of the animus. 


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With all this in mind, we should be able to get some idea of what this dream means.

You and your friend are in a church.  The church represents you in some way -- probably your psyche.  This is a positive beginning for dream. 

She showed you something she had found.  It was "a creamy crystal in the shape of a flat triangle."  I would usually consider a crystal in a dream to be a good sign.  But, the crystal is creamy and is in the shape of a triangle.  The creamy color of the crystal could be a sign of its having impurities.  And, it has three corners rather than four.

Once she shows you the crystal, the rapper appears. 

Do see what is happening?  Each event "causes" the next.  Being in church is good; thus, the good thing that happens next is when you are shown the crystal.  The most significant thing about the crystal is probably that it was found by your friend and not you.  This "causes" the appearance of the rapper.  But, why? 

Remember that the rapper is a symbol of your animus.  He became violent because he is jealous.  This is a fairly common theme in many of the dreams that I look at.  It is the conflict between human archetypes when one gets very little attention.  In the case of the animus, he is desperate for attention.  "Bad" attention is better than none.

Back to the crystal --
The crystal may be less than perfect.  In addition to being creamy, it has three corners rather than four.  The number four is a common sign of being whole while three is, apparently, less than to being whole.  It is tempting to think of the triangle as symbolizing you, your friend and the rapper.  And maybe it does ? however, the triangle could instead represent you, your friend and the wife.  These three plus the animus would be personifications of the four ego functions: Sensation, Thinking, Feeling and Intuition.  They describe how we experience and learn.  They describe how we process information and make decisions.  They describe how we interact with the world.  As shown by the figure at http://www.kheper.net/topics/Jung/typology.html , Intuition is opposite Sensation and Thinking is opposite Feeling.     

You wrote that the rapper had a long penis with a knot in the end.  This probably means that there is a blockage in the flows of his masculine energy.  When you bravely confront him, he changes into the Hulk.  Although he doesn't seem to have much experience with women, his penis is normal.  Thus, his male energy is normal.  This seems to be a step in the right direction.  You are helping him to become a normal man.

Hope this helps (and is not too confusing),
Lugus