Ten years ago, Mukhtar Ablyazov stepped out of Kazakhstan's notorious Derzhavinsk prison with a pledge to give up politics. Ablyazov, a "wild '90s" oligarch and rising force in Kazakhstan's nascent opposition, had served just 10 months of a six-year sentence for illegal financial deals. But it had been enough. During his time in prison he had reportedly been beaten, placed in isolation, and denied access to his lawyers.