Right, well, the question has been answered.
BUT
We have a dilemma, in that the two halves of it were answered by two different people.
Loudhy got the game right: 'Ultima 7 (Part One), The Black Gate'.
(BTW, Ultima 6 was 'The False Prophet', and centred around the war with the Gargoyles. Serpent Isle was 'Ultima 7 Part 2'. I have no idea why they didn't just go ahead and call it Ultima 8...)
But
Nightowl2 got the character right, being The Guardian (quite possibly the coolest villain of all time, except for in Ultima IX, where he sucked, big time

).
However, I'm assuming that Loudhy didn't see the additional 'name the character' question, and since he was able to name the game it seems logical that he
would've been able to name the character too (the Guardian is the only 'voiced' character in the whole game afterall).
Soooooo, sorry
Nightowl2, it was a good effort, but I'm gonna award this one to
Loudhy.
So.... batter UP!
ps: sorry for taking my sweet time in answering fellas.