They're both certainly short and punchy enough, but I will offer some suggestions for alternatives:
Series Pitch: I don't know how helpful it is at this level for a reader/agent to be given Sauron's name as a benchmark for levels of evil/being reviled, because we know nothing about him/her. So instead, how about this:
Driven to unimaginable evil, universally reviled: this is [insert MC's name]'s story/journey into the depths of ____.
It's still only about 15 words, so you've got wriggle room for a couple of helpful adjectives and additional snippets of detail if required.
Book 1 Pitch: This may be just a personal preference thing, but I didn't like the succession of questions here. I am also unclear if "the outcast he despised" is in the running to succeed him (I'm assuming yes?), so I would like that to be clarified. How about this instead, then:
The king has been murdered. Many are vying to succeed him. Where does this leave his outcast and reviled true heir? (21 words)