LOL a genocidal maniac? Nah, not really... He didn't have to do much, most of the "dirty work" has been done already by Enver & gang (Armenian genocide) and the stupidity of the Greek leadership (that brought the destruction of the Greeks in Asia Minor) dealed with the "Greek issue" as well (with the mutual population exchange).

But Kemal was fixed on creating a "Turkish Nation" and he did initiate a series of ethnic cleansing campaigns, mostly aiming at asimilating the 100s (literaly) of different ethnic groups residing in the lands of the young "Turkish republic" into one 'Turkish nation'. Most assimilated, but those that didn't (Pontic Greeks, Kurds, for instance) were subject to more... drastic measures. I wouldn't call it "genocide", but it was ethnic cleansing for sure. So,yes, he was "good at purification" as Romanus puts it... before Kemal only the young Turks spoke about 'a Turkish nation'. With Kemal, there actually a Turkish nation was created. Downside is that it had to absorb every other nation living inside the once Ottoman land of Asia Minor...

He wasn't an angel, that's a given, but he wasn't "a genocidal maniac" either... just a ruthless, extremely intelligent, very fixed on realpolitik nationalist leader.