Temari from Naruto is so cool and badass but sadly we rarely see her. She has the Wind Release nature and can summon Kamatari (the one eyed weasel) with her fan to cut up her opponents. She's blunt and not afraid to speak her mind and is overall a really amazing character.
She isn't the main character, but shes always with the main character, and plays a huge role in the anime. If you have seen it, you will know what I mean.