Although Nietzsche uses the term 'leeches' and 'vampires', this isn't in the context of a 'mind control parasite'. And whilst he also uses the term 'parasite', he certainly doesn't ascribe it powers of 'mind control'. Whilst N often uses hyperbolic and metaphorical language in his writings, I don't think I have come across that specific term and that you have put it in quotes suggests that you had read it somewhere in his work. Can you say where?
In Thus Spake Zarathustha, Z stumbles across a man lying down in a swamp with several leeches on his arm and when Z asks him is he studying the leech, he tells him no, he is studying only the brain of the leech. He says to Z:
"I am the conscientious in spirit ... and in the matters of the spirit there may be none stricter, harder and narrower than I ...Rather know nothing than half-know much better to know nothing ... A hand-breadth of ground - on that one can stand. In the conscience of science there is nothing great and nothing small ... That of which I am the master and the expert is the brain of the leech. That is my world ... that is my realm. For its sake I have thrown away everything else. For its sake, everything else has become indifferent to me. And close to my knowledge lies black my ignorance ... Where my honesty ceases, I am blind and want to be blind."
Z is parodying the scientific and objective spirit. This had already been down by Swift in his Gullivers Travels where he pokes fun at Balnibarbins for an eight year research project to extract sunbeams out of cucumbers and attempting to turn human excrement back into food. Nietzsche's aim here is to describe and dismiss what he considers a failed form of his 'higher type'.
In aphorism 260 of Human, all too Human, he writes:
260: Prejudice in favour of size: Men clearly overestimate everything large and obtrusive. This comes from their unconscious insight that it is very useful if someone throws all his strength into one area, and makes of himself, so to speak, one monstrous organ. Surely, for man himself, a uniform cultivation of his strengths is more useful and beneficial, for every talent is a vampire that sucks blood and strength out of the remaining strengths; and excessive productivity can bring the most gifted man almost to madness. Even within the arts, extreme natures attract notice too much, but a much lesser culture is also necessary to let itself be captivated by them. Men submit from habit to anything that wants to have power.
Again, it's hard not to hear Nietzsche reflecting on himself here, even if he does not name himself. His language is hyperbolic as though he has thrown "all his strength into one area". And here he also recognises - rather belatedly - that strength is not always all its cracked up to be. It can turn 'vampire' sucking out life and vitality.
The quote you refer to is also from Nietzsche's Human, All Too Human:
Parasite - It indicates a complete lack of nobility of disposition when someone prefers to live in dependency, at the expense of others, merely so as not to have to work and usually with a secret animosity towards those he is dependent on - such a disposition is much more frequent amongst women than men, also much more excusable (for historical reasons).
This appears unobjectionable, but of course there are many situations where peiple are dependent, children, the elderly and the sick. One would think Nietzsche woukd exclude these from being parasitical dependents. But no, for he also refers to this term in The Genealogy of Morals, where he writes:
A moral for doctors - the sick man is a parasite of society. In certain cases it is indecent to go on living. To continue to vegetate in a state of cowardly dependence upon doctors and special treatments, once the meaning of life, the right to life has been lost, ought to be regarded with the greatest of contempt by society. The doctors, for their part, should be the agents for imparting this contempt, - they should no longer prepare prescriptions, but should every day administer a fresh dose of disgust to their patients. A new responsibility should be created, that of the doctor - the responsibility of ruthlessly suppressing and eliminating degenerate life, of ascending life, demand such a course ... one should die proudly when it is no longer possibly to live proudly. Death should be chosen freely, - death at the right time, faced clearly and joyfully and embraced while one is surrounded by one's children and other witnesses.
A wonderful, brilliant insight. His pen drips with genius. How could we have been so blind all these millenia? Sick people are parasites and the sicker they are, the more parasitical they become. Get rid of them. Better, make them get rid of themselves. It's cheaper and less labour intensive.
Nietzsche wasn't writing about natural philosophy or the philosophy of logic but about how we ourselves are to live, hope and dream. Thos is why he is a moral philosopher, even if he calls himself the anti-moralist. Such philosophies have to be lived for them to mean anything and by the author if the philosophy has to have any degree of authenticity behind it. Well, life, a word that Nietzsche loved and praised gave Nietzsche a chance to just exactly that - to live out his philosophy. He famously became mentally ill at the age of 45 in 1889 and then lived in the care of his mother until her death in 1897. And then with his sister until his own death in 1900.
He was sick for ten years, dependent first on his mother and then on his sister. Did he think 'it was indecent to go on living?' Did he think he had a 'complete lack of nobikity of disposition' living dependently on his mother and then his sister? Not for a few weeks, here and there - but for a decade? Did he think he should 'die proudly when it was no longer possible to live proudly'? It's hard of course to know what he thought in that state. But the facts speak for themselves. No 'proudly' embraced death for him 'faced clearly and joyfully'. No jumping off cliffs. No shooting his own brains out. Or cutting his wrists. It seems he would rather prescribe medicine that he would rather not take. So much for his doctoring.