Amora, beguiling Asgardian witch, made her debut in 1964 when Thor's adventures were still in their Journey into Mystery infancy. She initially is working for Odin, who sends her to earth to eliminate Thor's human love interest, Jane Foster, since the All-Father isn't keen on his son Goldilocks frisking around with a mortal when he should be working on his Sif game. Amora is all too happy to help, but when she fails, Odin banishes her and her minion Skurge (the Executoner) to Midgard (Earth). The Enchantress becomes one of Marvel's earliest female villains, and remains among their best today (I was never a Mystique guy, or a White Queen guy - and yes, Emma Frost will always be a villain to me). She proves an ongoing thorn in the side of the Avengers in general and Thor in particular.
The Enchantress is driven by cruelty, control, and vanity: she uses her vaunted beauty to seduce enemies and allies alike as she advances her own sometimes oblique agenda. (Poor Skurge trails along behind her like a lovesick eighth grader, looking for table scraps of attention that rarely fall his way.) She'll work with Loki, and with human allies at need. Her main target is Thor, and it's here that the character of Amora displays some complexity and nuance. She wants Thor because he's as beautiful as she is, a quest spurred in equal measure by ambition as lust. And yet at times, cracks in the veneer show, and we see that there might actually be shreds of legitimate affection and attraction. Even Thor sometimes considers her appeal, despite her evil track record. Maybe there's more there, and what she needs is someone to believe in her. Or maybe she's just that stunning (and Thor likes the ladies).
As I've observed before, my introduction to Marvel came by way of the 1984 Secret Wars limited series. It was during this storyline that Amora came perhaps her closest to truly communicating with Thor, as the two immortals slipped away to - ahem - talk over over the bizarre situation the Beyonder had put them in. It seems the weak, deeply-buried better angels of her nature are trying to emerge with Thor's encouragement, but when she refuses to help him against the villains, the moment is lost. In 1984 I was nine, and pretty much seduced by the Enchantress myself - leggy, blonde, improbably shaped, and with archaic patois that made her nasty comments vaguely sexy. It was my first exposure to the concept that beauty might mask evil, that a pretty face doesn't always mean a pretty soul.