In the immediate aftermath of the Chinese Civil War, the KMT government saw itself as the legitimate government of all of China, though it was 'temporarily' based in Taiwan. Till today, Taiwan calls itself the 'Republic of China', even though it is largely nominal.
As for exactly how brutal the KMT was, I cannot offer a definitive historian's perspective because that is still a work in progress. Having spoken to many Taiwanese people though, it was pretty clear that it was a very repressive period. Apart from this, I won't challenge your own view of the matter.
In any case I didn't cite the White Terror period to justify the CCP's brutality on June 4 which I abhor; I did it to point out that there were other periods of bloodshed almost, if not just as bad.
we are talking about China. btw, the White Terror period of cruelty had been greatly exaggerated by the anti-Chiang, Kuomintang peoples and Taiwan Nationalists over the decades to make the suppression period seemed worse than it really was...