Darkness or Light? Philosophy in Knights of the Old Republic.

That's an interesting point. When destroying a planet with billions of inhabitants, he spared only ONE. That's the height of mercy. I haven't played Kotor 2, but if you say there are interesting conversations with companions, then I recognize the hand of a master:)

-"If you order your old and faithful servant to carry out a task and he fails, will you spare him?" - Uthar Wynn
-Yes - The protagonist of Kotor 1
-And in doing so, you will show your weakness! Go, you don't understand the Sith Code!"
And also, about love:
-"Is it true that love is the worst thing?" - Uthar
-Yes - The protagonist of Kotor 1
-That is not true! Mercy is worse than love (it implies that love is slightly better than mercy).
In my opinion, the Sith don't recognize love, but passion, and these are not the same thing. Love can prevent a person from achieving power, which is the Sith's top priority, while love implies that the number one goal is oneself, and not something else.