Perhaps someone more knowledgeable on the Rule of Two like DMD can give his insight as well.
I can understand them taking satisfaction in both the things you mentioned, because oddly enough, I have relished the same events for years now.
Get ready for another "Kurk" moment:
a.) the potential satisfaction of knowing they had trained their apprentice/successor adequately
If I had to choose my death I could list a several options, but at the top of the list would be death at the hands of my superior; whether that be physically, indirectly, intellectually, etc.
Recently I've been contemplating the idea of adopting an orphan once I am financially stable enough to do so. I would raise this kid as my apprentice, not my child, and teach him/her everything I know. Once old enough, I would grant my protege a position in my law-firm/business, expecting them to quickly ascend through the ranks and bring in clients better than I can. I would expect to be made obsolete by my apprentice's effectiveness at some point in time (The orphan would be carefully selected by considering their gene pool and ensuring that they are meant to be my superior in IQ, health, etc—hopefully genetic engineering is available by then). Once they reach that point, I would concede my position of power to them as a symbolic means of failure/death, and plan to die shortly thereafter.
This really appeals to me for some reason, but I can't find the words to describe it. Just thinking about it makes me feel like Tenebrous did as he was dying at the hands of Plagueis.
or b.) the potential satisfaction of knowing that it took a Jedi embracing the dark side(essentially throwing away his/her own beliefs) to kill them... That's just how Sith think.
I have also experienced this and unsuccessfully tried to implement it in my highschool life.
In highschool, I was in the top quarter of my class, but by no means the tip-top scholar. I was able to contend with the saludictorian, but was not their equal. Their flaw was their kindness and willingness to help lesser students. I loathed this flaw and saw the potential this person possessed if they learned to stop their benevolent behaviors. I encouraged this person to (figuratively speaking) destroy me in projects and such through aggressive means, but they were too nice to be turned hostile and humiliate me in front of our peers. I fantasized for months about this person using their intelligence to attend an ivy-league (which they did) and eventually become a hedge-fund manager on Wall Street. Instead they pursued medicine. Such potential wasted.