Long-lived people are well-explored in fantasy and sci-fi, they just use mostly same tropes as immortals, to the point the distinction becomes nearly irrelevant.

Ditto for "positive" versus "negative" undead. Vampires, for example, have been romanticized to Hell and back, and even in serious vampire stories can be completely benign and well-adjusted. Typically they're a far cry from devils inhabiting corpses and flesh-eating ghouls folklore, or even the predatory sociopaths of Stoker.