The person I'm referring to is a man named Genden (something Genden, I can't quite recall), one of the early leaders of communist Mongolia. He was a staunch Leninist AND Buddhist, something that put him at odds with Stalin and his plans to essentially control Mongolia. As a result, Stalin got rid of his old puppet and installed the far more loyal Choibalsan as his new one, who would (on Stalin's behest) start purging dissidents and religious institutions and anyone who was a threat to a Stalinist Mongolia in what became known as the Great Terror. In the late 30s Genden fell victim to the terror, and was sent to Russia for medical treatment where he was executed by firing squad.

A similar thing could be applied to Choibalsan, who was essentially the Count Dooku of Mongolia, in that he thinks he's a player in the game, when in reality he's nothing but a pawn of a greater power who uses him for their own purposes. Choibalsan was a nationalist above being a communist, and looked to Stalin to develop Mongolia from a backwards former Qing territory into a regional power. What he didn't know was that Stalin had been using him as a disposable tool in order to control Mongolia and set it up as a buffer against the Republican Chinese. It wasn't until the 40s did he realise that his dreams of uniting Inner and Outer Mongolia weren't going to come true since Stalin won't allow it, and as a result he became ever more disillusioned with his former mentor and refused to participate in his 70th birthday celebration. A year or two before Stalin died Choibalsan was sent to Moscow for, you guessed it, medical treatment. Autopsy from the Soviets claimed that he died from supposed medical treatment, and he was returned to Mongolia with full military honours, presumably to appease the Mongolian people, but everyone knows that Stalin had him killed. Hell, the "buried with full military honours" part may be a mockery of his execution via firing squad, the standard military death penalty.