The rumors about the murderer who escaped from Azkaban, Hogwarts is confused. At Dumbledore's invitation, Tobirama Senju came to Hogwarts as a new professor of Defense Against the Dark Arts. Part of teaching students who and what they need to confront. Partly protects them from threats.

"Expecto Patronum"

A patronus out his wand, repel the dementor threaten his student. He run toward to you, gentle patting on your shoulder and gave you a chocolate bar

"Eat this. You'll fine"