This dream is related to the game Kingdom Hearts.

Okay my dream started with me in front of my school just like every morning except that my best friend in real-life wasen't there for some reason.I went to my 1st period class and for some reason I kept having this forboding sense of fear.Suddenly everything turned so dark that it looked like midnight.My eyes became accustomed to the darkness after a few minutes and everybody around me became a heartless and tried to kill me.I ran out of the classroom closely followed by all those heartless. I ran about two miles from the school and ran into my friend's house and nearly fainted from the gashes that those heartless left in my arms and legs.I suddenly saw my friend and he had two keyblades in his hands.He threw me one which turned out to be the Oathkeeper.With the Oathkeeper in hand myself and my friend fought off the heartless in his house.The heartless suddenly stopped coming and left us alone.Suddenly my friend told me to come with him and I began to follow him.I suddenly stopped because something didn't feel right.My friend turned around and asked what was wrong.I pointed my keyblade at him and he started to laugh. I told him to shut up.He began to charge at me with his keyblade.I parried him and started to fight him.I suddenly slashed through him and he disappeared in a dark mist saying that he wasen't dead yet.

Could anybody explain this dream to me?

I don’t really know anything about the game, seems like some kind of big adventure Disney/Final Fantasy type scenario.

I wonder if you are wondering about who your real friends are? But you also have to take into account how much you play the game itself in waking life, computer games and dreams are very similar sometimes and the similarities often overlap into your dreams. Could be a case of too much computer games, especially if you play it right up to bedtime.