Still on Buffy, somewhat but not entirely.
The Triumvirate hero concept seems to be a trend in the sci-fi/fantasy genre, doesn't it? I've figured out 3: Luke/Leia/Han; Harry/Hermione/Ron; and Buffy/Willow/Xander.
And they have one thing in common in that, while there may or may not be relationship between the 2 sidekicks [Leia/Han; Hermione/Ron; Willow/Xander], there never is between the hero and any of the sidekicks.
Interesting...