I pretty much know nothing about it, and would like to learn.
Wikipedia is probably terrible, and I don't know where else to go besides there.
Also, let's throw in some information about the DPRK too while we're at it. All I've ever read about them are ridiculous stories about how they consider Kim Jong-Un to be a god-king and that they set up entire fake cities to fool western tourists.
It's the body that appoints officials, enacts laws, and amends the constitution as well as drafts the 5 year plans. It's outside the party (it has other party officials inside it, including KMT members), but is still mostly controlled by the party because of the high ratio of party members.
I think the party still has final say? Like let's say a small group of Taiwan Democratic Self-Governance League and Revolutionary Kuomintang members decided they wanted to put up a vote about bringing the dynasty back or something, the party sould just shut that down.
I'm not totally sure exactly how that works though.