I am very confused. it seems the KMT is against the DPP. I know Chiang Kai-Shek was the leader of the KMT who landed them in Taiwan. I know the DPP has also recently banned the KMT. Why?

Why is the Ex-Chair of the Chinese KMT appearing in CGTN and talking about the mainland helping reunification? Can someone help me understand the situation? Has the KMT changed? I thought the KMT hated the the CPC.