One of the reasons it can be so hard to convince other people that the narcissist is dangerous and evil is because of the altruistic image many of them often present to the world. My entire lifetime I have been an observer of my mother's relationships (including with myself) and have seen how in every single one of them she made sure she was perceived as the benefactress. In her mind, her position of "giver" is one of superiority. To the narcissist it is a sign of inferiority to ask for help; a sign of superiority to dispense help. This is a hard and fast principle with narcissists so you better commit that one to memory.
Her giving came in several forms: she would give of her time, her knowledge, and sometimes her resources. The narcissist knows the most dependable source of supply is to make another person dependent on them, so they encourage dependence. They know that being dependent is habit-forming so they are anxious to encourage you to this end. It makes for a steady source of narcissistic supply for them. They do nothing without a calculation of what they will be getting for what they give. This is not altruism. There is not an altruistic bone in their bodies. Do not be fooled. Your dependence is their guarantee of supply. It is all about them.
The dependence may be either financial or emotional. My mother specialized in the latter because she didn't have endless resources. She is a very greedy person and more likely to take your material things than to give you hers, unless we are talking about her discards. She will make great fanfare of generously giving you something material when she is really just throwing it away. Why put something in the trash or give it to Salvation Army when she can gain an opportunity to support her image of self-less generosity by giving her junk to you? You, of course, are not allowed to say, "What a piece of junk." No, you must look appropriately grateful for her generosity and tell her how perfect the "gift" is. Your humble reception of her "generosity" is what turns her "gift" into narcissistic supply for her. Then you'll have to surreptitiously throw it in the trash and hope she doesn't ask you about it later. A small little anecdote to illustrate. My mother gave a female cousin of mine a bag of soap slivers. My cousin was accustomed to watching the budget so as to stretch the home finances. So my mother decides that my cousin is "poor". Poor enough that she should be thrilled to accept a gift of soap slivers! By soap slivers, I'm talking about that little piece of soap you can no longer hang onto in the shower so you throw it away. I had seen this netted bag with soap slivers in my mother's bathroom cupboard some years earlier, so I knew of this soap sliver collection. I had no idea why she was collecting them, but wasn't curious enough to ask. I think it is very likely she didn't know what she was going to do with them when she started either. But, lo and behold, the day finally came when she could discard this insane collection. She could use it in a transaction that would turn old, crusty soap slivers into the stuff of life...narcissistic supply. Narcissist alchemy. Turning lead (soap slivers) into pure gold (of narcissistic supply).
My mother has honed her nurturing of dependence so that even while she is rushing to your aid and encouraging you to depend on her, she tells you how she will teach you to depend on yourself and not her. Which makes her sound like a true beneficent. It encourages you to trust her completely. The course of time reveals the lie, though. Even while she is acting like she someday expects you to depend on yourself she is drawing the bands of control through dependence ever tighter around you. You will not escape except by a supreme act of the will and a determined cutting off of all contact. She is obligating you to her with every act of beneficence. You are expected to show your loyalty and your supreme adulation and gratitude with every interaction. Any deviation from an attitude of admiration will bring down the judgment of heaven on your head. She will remind you of the great sacrifices of her time and knowledge given to you in your time of extremity; how could you think she is anything but self-less and wonderful? You feel ashamed to think even one thought that deviates from the image she projects. To put it succinctly, there are strings attached to every single thing she does for you.
Unfortunately, she does not follow the Biblical injunction to not let the right hand know what the left hand was doing in her acts of "charity". No, she made sure that others in her life knew of the great sacrifices of time, energy, and knowledge she has exerted on your behalf. She does this casually. No need to make a great show of it. No, if she drops the information casually it doesn't appear to be bragging, it just appears to be evidence of how naturally she gives of herself to others. There is a strategy to all of this. She is constantly aware that at some point her dependent may attempt to defect from her iron-fisted control. She is taking out insurance against this possible outcome. She is insuring her image to others. The uprising of indignation when you try to assert some control of your own life will astonish you. Suddenly, everyone around you is frowning on your behavior and reinforcing the narcissist's claims that you are a selfish ingrate. Unless you are very sure of your own mind, it will be hard to defect in the face of such overwhelming opposition. You can not leave the narcissist's lair without suffering a very large hit to your reputation in the eyes of others. Those "others" are mutual friends or family so it is painful. You're going to have to face the fact that you will have to look "bad" in order to reclaim your dignity and your autonomy. Look at this as a time when you will find out who your real friends are.
As a beneficiary of the magnanimity of the narcissist you become the silent audience to their grandiosity. You are privy to their one-man show. You come to realize it is all about them and not about you at all except what you give them. You must be forthcoming with generous servings of admiration, respect, even fear. It really isn't all that important to the narcissist to be loved. They are satisfied with admiration or fear of the image they project. Those two responses appeal to their grandiose view of themselves. The narcissist reveals how it is not altruism that motivates them because they very quickly lose interest in being helpful when they are not receiving applause for their actions.
Be assured of this fact; every favor you receive from the narcissist incurs debt. You can never repay this debt. Never. He is the only one allowed to tend to the bookkeeping ledger...and that ledger is always going to be used to prove you are forever in debt to him. Forever. Any favor you do for the narcissist was simply what you owed him. In other words, you are not able to grant a favor to a narcissist. This would prove that he needed something, which is anathema to his god-like status. You can't do favors, you can only pay in some small way toward your "debt". There is no fairness in this system, so don't look for any. If you can be satisfied with a lifetime of being a lesser form of life who has incurred an eternity of debt, then stay dependent on a narcissist. Otherwise, cut your losses and get the hell out of Dodge.