Stalin

When Lenin died in 1924, everybody expected Trotsky to take over the leadership.   Instead, Stalin schemed his way into power, using his position as General Secretary, and a series of ruthless political moves .This is how Stalin came into power; cheap schemes and wide rhetoric to beat out his only competitor. In many ways Hitler and Stalin were similar, except for the fact that we had an alliance with Stalin! We were allied with a murderer. What country are we, huh? 

No one exactly knows the exact number of deaths Stalin came to create, but to me, the answer is simple. If a dictator has people imprisoned or sent to camps, then he's ultimately responsible for their fate, so there is little distinction between killing people and deliberately letting them die of neglect.
The gap between high and low estimates is enormous. At the upper end one gets estimates ranging from about 40-60 million or even 100 million, at the lower end about 10-20 million. Clearly, there's ideological 'monkey business' at work. Until someone can reconcile these amazing discrepancies satisfactorily, and provide a very clear explanation of how the new figure is arrived at, it's impossible to say how many people Stalin had killed.

A murder is a murder; A life is a life; Death is death, no matter who dealt the last blow. 

He killed them. Each and every one. Maybe not by his hand, but by his orders, his rule and his own means.