Who is the antagonist in Unfinished Tales: The Lost Lore of Middle-earth?

Antagonists abound as the stories are not set in peaceful times. There is no happy ending. There is only war after war, and these wars are going on in the background of most of the stories and influence the actions of the main characters. Morgoth and his minions cause the first conflicts. Although the stories don't go into details about Morgoth, he is always there in the background, giving every story a gloomy feeling and a sense of urgency.

Sauron comes next. According to the chapter on the Istari, Sauron is not as powerful as Morgoth, and yet he is still a great threat, great enough for the Valar to become involved with by sending the Istari to Middle-earth.

Saruman is the third evil influence. He is, in turn, not as powerful as Sauron, yet still powerful enough to bring Isengard under his control and bring about the deaths of many Men. The great irony of this is that Saruman is originally one of the Istari that the Saruman send to Middle-earth to keep Sauron in check.

Finally, it must be mentioned that there are many lesser antagonists in the stories, such as the Orcs, the Easterlings, and the Wainriders. These are usually described as being servants of one of the three greater protagonists (Morgoth, Saruman, and Sauron), though.