The immediate series that springs to mind is 'Made in Abyss'. Honestly, its fantasy world is the most uniquely terrifying and beautiful one I've encountered in a long time. The whole setting is built around this massive, seemingly bottomless pit called the Abyss, with each descending layer having its own impossible ecology, relics, and curses. It’s a world that feels genuinely mysterious and dangerous, not just a pretty backdrop. The lead, Riko, is a fantastic counterpoint to that. She isn't physically overpowered at all, but her driving motivation—this obsessive, academic curiosity to reach the bottom and find her mother—is her real strength. Her resilience is mental, not magical, and she navigates a place that physically harms you for trying to leave it. It’s a brutal setting where knowledge and sheer stubborn will are the only tools you have, which makes her journey so gripping.
I'd also toss in 'Dungeon Meshi' for a completely different, but equally unique, angle on fantasy. The setting is a classic dungeon crawl, but the twist is that the entire economy and survival strategy revolve around cooking and eating the monsters. The female lead, Marcille, is an elven mage who starts off as the somewhat stereotypical 'sensible one' in the party, but she quickly becomes the emotional and strategic core. Her strength is in her deep, sometimes obsessive, academic knowledge of magic and dungeon ecology, which constantly clashes with the more pragmatic approach of the others. Her development from a rule-follower to someone willing to question the very foundations of their world’s magic system is brilliant. The fantasy here feels lived-in and systematic, with its own internal logic that the characters are constantly trying to understand and exploit, which Marcille is central to.