Honestly, I'm getting kind of tired of the 'villainess is actually secretly a cinnamon roll' trope. For a genuinely complex lead, I keep coming back to 'Your Throne.' Medea is ruthless, brilliant, and her moral compass is practically a roulette wheel. She’s not just a reformed baddie; she actively schemes and manipulates, and you're never quite sure if she'll do the 'right' thing. Her complexity isn't in her backstory trauma, but in her present-day calculations and shifting alliances.
Another one that doesn't get enough credit is 'The Villainess Lives Twice.' Artezia is so cold and methodical it's chilling, using her knowledge from her past life purely for political survival and revenge. There's no sudden sweetness, just a deeply pragmatic and wounded person navigating a world that wants her dead. Her complexity lies in the sheer weight of her choices and the loneliness of her path.
On a slightly different note, 'Roxana' also deserves a mention. The atmosphere of that manhwa is oppressive, and her character is built on survival in a family of monsters. Her complexity feels more like a slow-burn reveal, peeling back layers of trauma and resilience.