According to Lenin, socialism is the dictatorship of proletariat in the sense one class dictates its will to the others. Similarly, in his view capitalism is dictatorship of the bourgeoisie.
According to him, dictatorship of proletariat is the highest form of democracy because the power belongs to those who works and produces the goods, and also proletariat is (at least was at his time) the largest class numerically.
A person who adheres to these views is properly called SocialistMarxist-Leninist or Communist.
A dictatorship of a person or a close circle would be thus contrary to Communist principles.