Has anyone here ever had a party end their relationship/association with a mentor in a way that you felt was particularly satisfying?

If so,

• What was the relationship between student and mentor like?
• What caused it to end?
• What about it worked well/badly?
• How did your players react?

I'd love to hear your stories. Long replies are welcome.

I am currently playing a 16 year old (now 18) padawan who escaped the jedi temple during order 66. Finding a Jedi, who also survived, in the rubble of 66 he took me as a padawan. I sacrificed my myself to become Vader's prisoner to get my friends ship, carrying younglings, to safety. I've learned all my master's powers, so once rescued I imagine our relationship will become more like Obi-wan and Anakin in Revenge of the Sith. Minus the trying to kill each other part. Maybe.