A
Minbari from
Babylon 5 Thrall was a good
friend and
mentor to Delenn, one of the main characters (also a
Minbari).
He ended up becoming the caretaker of "The Great Machine" an utterly enormous technology complex buried deep beneath the surface of the planet Babylon 5 orbits.
One of his lines is my favorite quote from the series - on self sacrifice and its relationship to the nature of sentient life.