Sankara took power in a military coup himself. While he led positive reforms such as literacy and vaccination campaigns, he also banned trade unions and the free press. His Committees for the Defense of the Revolution and Popular Revolutionary Tribunals engaged in torture, execution and arbitrary detention. It’s hard to find unbiased accounts of his rule, as anti-communists tend to ignore his achievements while communists have practically declared him a saint, but I’d take hagiographic accounts of the man with a grain of salt.