Dependent is defined as weak, helpless, defenseless, reliant, vulnerable and subordinate. The narcissist enables, promotes, propagates and supports the mental state of being dependent on them. This transfer of personal self worth and power is then given to the narcissist to create a co-dependent atmosphere for consistent and reliable supply. The narcissist also creates a dark drama on a reel of film for you to watch over and over again in your mind.
The main character is projected as the blameless and virtuous while the true victim is guilty of all. The narcissist helps the audience to boo, hiss and throw tomatoes at the vile scapegoat while they themselves get standing ovations and cheers. It's the fun house of mirrors with designed and established false illusions to trap their target into believing a false reality about themselves.
The innocent is transformed into a martyr hoping to escape from the nightmare generated and produced by the narcissist. But what is their escape? For everything to be normal like having a picnic on a warm sunny day with the narcissist.
Thus the co-dependency lives on because the martyrdom has been programmed into their minds to believe and hope that the narcissist will change. Unless the narcissist realizes their behavior is evil and there is something seriously wrong with their behavior, gets help medically or otherwise the narcissist will not change.
When a person grows up in a narcissistic world they can become a narcissist themselves. The only way they can function is to do evil.