Luna Lovegood
At Dobby's funeral, Luna gave a nice eulogy which calmed everyone, thanking Dobby for rescuing them all from Malfoy Manor. Later when Harry had to find Ravenclaw's lost diadem, Luna escorted him into the Ravenclaw common room, where she also stunned Alecto Carrow, a Death Eater. At the Battle of Hogwarts, she cast her Hare Patronus, which made several approaching Dementors leave, and she also fought Bellatrix Lestrange. After the Battle, Luna created a distraction, so that Harry could be alone.