Bellatrix Lestrange

Bellatrix was still fighting, about fifty paces away from Voldemort, and like her master, she was fighting three people at once—Hermione, Ginny, and Luna. They fought with all their might, but Bellatrix was their equal, and Harry's attention shifted when the Killing Curse flew so close to Ginny that it missed her by an inch…
Harry turned and ran not toward Voldemort, but toward Bellatrix, but before he'd taken more than a few steps, he was shoved aside.

• DON'T TOUCH MY DAUGHTER, BITCH!
  Mrs. Weasley threw off her cloak as she ran, freeing her hands; Bellatrix spun around and burst into laughter when she saw who was challenging her.
  "GET OUT OF MY WAY!" Mrs. Weasley yelled at the three girls, and with a quick wave of her wand, she began the fight. Harry watched in horror and delight as Mrs. Weasley's wand spun and sliced ​​through the air, and Bellatrix's smile turned into a snarl. The wands emitted jets of light, the floor beneath the witches' feet smoked and cracked; the fight was to the death.
  "No!" Mrs. Weasley shouted as some of the students ran to help her. "Back! Back! She's mine!"
  Hundreds of people now stood along the walls, watching the two fights, Voldemort with his three opponents, and Bellatrix with Molly, and Harry stood between them, invisible, wanting to attack and protect, and afraid of hitting his own.
  "What will happen to your children when I kill you?" Bellatrix sneered, as furious as her master, dodging Molly's spells as they danced around her. "When Mummy goes after Freddie?"
  "You will never touch our children again!" Mrs. Weasley screamed.
  Bellatrix laughed, the same joyful laugh her cousin Sirius had given her as he fell backwards through the veil, and suddenly Harry knew what was coming before it happened.
  Molly's spell flew under Bellatrix's outstretched hand...