Probably more than anyone else, Fritz Platten, a Swiss Communist, was instrumental in getting Lenin into Russia in 1917. He also saved Lenin's life:

Fritz Platten was also present when Lenin's car was under attack in Petrograd on 14 January 1918. The two were riding in the back of the car together after having given a public speech. When the shooting started "Platten grabbed Lenin by the head and pushed him down. ... Platten's hand was covered in blood, having been grazed by a bullet as he was shielding Lenin."

What was his reward for his undying belief in Communism, and service to the Soviet state?

Platten became a victim of the Stalinist purges of the 1930s. He was arrested in 1938 and moved to a prison camp near Nyandoma in 1939, where he was shot on 22 April 1942.

Four years of starvation, cold, and forced labor in a Russian prison camp near Archangel, Russia. And then a bullet through the head. And yet he'd truly believed. I wonder what he might have thought in those last days.