Everyone loves warriors who can beat down those who stand in their way. Anime has no short supply of them, thanks to the vast quantities of fantasy and action shows out there. Girls with guns? Girls with planet-destroying magic? Anime will scratch that itch you have for unstoppable warrior women.
For this particular list, we're focusing on melee weapon-wielding warriors. Other awesome women like Revy, Seras Victoria, Android 18, Yoruichi, Megumin or Sailor Moon, who primarily use guns, fists or magic in combat, don't qualify. The following women are the types who could cleave you in two or fight armies with a sword in hand.
Casca (Berserk)
Before Guts joined the Band of the Hawk, those who faced it in battle feared both its leader Griffith and his right-hand-woman, Casca. Saved from assault by Griffith, Casca immediately made a name for herself on the battlefield. She commanded the respect of the entire Band, becoming their leader during Griffith's imprisonment. Her technical skill with a sword is actually superior to Guts' -- though she isn't as ridiculously strong as him. While the two bickered during their early partnership, Guts and Casca would eventually enter a romance that ends in tragedy. She's still one of the few people to have experienced the horror of the Eclipse and survived.
Mikasa Ackerman (Attack on Titan)
In a world where gigantic Titans attack humanity's fragmented survivors, you'd have to be somewhat crazy to throw yourself at them with just acrobatic skills and twin blades, but Mikasa Ackerman is that special sort of titan-killing savant. Eternally loyal to Eren Jaeger after he helped save her from human traffickers, Mikasa quickly rose up the military ranks, becoming one of its most valuable officers. On top of mastering Vertical Maneuvering Equipment, Mikasa wielded the Thunder Spears to devastating effect. She's highly perceptive and determined to make a peaceful world -- which means carving through all dare threaten that dream, Titan and human alike.
Erza Scarlet (Fairy Tail)
Erza Scarlet might be known as a mage for the Fairy Tail Guild and its 7th Guild Master, but that incredible magical power comes equipped with mastery of every weapon she gets her fingers on. Ezra wields over 200 weapons in her arsenal, many of which she can manipulate without even touching. Erza's spatial magic allows her to switch her armors and weapons out with lightning speed. On top of being so skilled with a sword she can split metal apart with the sheer vibrations of her swords -- some of which she can swing with her feet -- she's a master archer, ax-wielder, defender and witch. There's little Erza can't handle.
Youko Nakajima (The Twelve Kingdoms)
Youko started off as an ordinary girl in real world Japan before being transported across the Void Sea into the Kingdom of Kou in a world known only as the Twelve Kingdoms. Once there, she's immediately forced to thrive in a world of treachery, betrayal and warfare against men and demons alike. She learns fast, becoming the heir to the throne as well as a warrior on the front lines of battle. Despite starting off a normal student, she becomes battle-hardened and wise through the heat of combat.
Maka Albarn (Soul Eater)
Daughter of Spirit Albarn, Maka is a student at Death Weapon Meister Academy, a special school that trains students to become master witch hunters -- or master weapons. Maka and her partner Soul Eater train to be among the best, with Maka aiming to turn Soul into a Death Scythe for the Grim Reaper. After training throughout the Soul Eater saga, it seems she has a shot at seeing this dream turn into reality. Despite only been a teen, Maka and Soul have already faced down a multitude of monstrous forces, including the villainous Medusa, her unwilling child Crona and, ultimately, the God Asura. The secret to Maka's strength isn't her power, but rather her wits, which allow her to even defeat Gods.
Sango (Inuyasha)
Sango is one of the few survivors of a village of demon slayers, trained to combat and subdue the demons scurrying around Feudal Japan. Even after the massacre, however, she continues her fight, helping Kagome, the half-demon Inuyasha and her pervy future husband Miroku gather the shards of the Shikon Jewel. Sango rides atop Kirara, a two-tailed demon cat, who can increase in size and power. Sango isn't absurdly strong, but she's a master of demons. Her massive advantage comes in the form of Hiraikotsu, a massive boomerang comprised of the bones of slaughtered demons, powerful enough to even knock back Inu-Yasha's sword Tessaiga.
Balsa Yonsa (Moribito)
Balsa claims to be just some bodyguard-for-hire in her mid-thirties, with only a spear in hand. However, as a child, she was pitted into a world of conspiracy and warfare, where eight men died protecting her. She vowed to protect eight souls in order to make up for those who died helping her. By the time she elects to defend a prince, she's become a warrior capable of warding off any adversary. In her many years in combat, Balsa has learned to subdue all who come her way.
San (Princess Mononoke)
The adopted daughter of Wolf Gods, San is a protector of the forests who wages a one-woman war against the people of Irontown and their leader Lady Eboshi. Lady Eboshi, while well-meaning, has invaded and destroyed the forest San calls home. Wielding spears and crude blades, San leads guerilla warfare on samurai and gun-wielding warriors. She's incredibly skilled at melee combat and has earned the trust of nature to aid her crusade, with her adopted wolf-god brothers letting her ride on their backs into battle.
Teresa (Claymore)
The former Number One Claymore, Teresa is regarded as the single strongest warrior to ever exist. Despite her incredible Yoki perception and skills with a sword, Teresa rarely needs to go full-out with her incredible power. However, with her Yoki abilities, her strength and power increase to absurd levels far outranking any other combatant. Known as a silent killer able to execute all before her with a faint smile, she evolved as a character thanks to her mentor-ship of Clare, the main character of Claymore. Even the Abyssal One trembles at the sight of Teresa's faint smile.