They don't often go bad, but when they do, they have been incredibly powerful and difficult to stop.
Which has been the best villain in your opinion? Whether you feel the most powerful , fiercest and challenging or the best written, best conceived, best executed/played out, or the most evil, destructive, influential night elf villain in wow? Whatever measure you use, which gets your vote? They don't have many, probably boast one of the fewest from a race, but the renegades do really stand out.
Who gets your vote? Even if it's merely your favourite night elf villain.
Queen Azshara?
Lord Xavius
Lord Illidan
Grand Magistrix Elisande
Arch Druid Fandral Staghelm
Warden Sentinel Cordanna Felsong
Twisted by the magics they fiercely devoted themselves too, a couple of these found redemption at/after death's door - and 1 of them's fate is unknown, still, despite how lawfully good this race is, they've made some of the most memorable baddies in Warcraft. Pick your fave.