Death Eaters!
Even before he could make out their figures, Harry was certain that the ones attacking Mrs. Weasley, Bill, and Pheobe were Death Eaters!
They had caused a huge commotion in London, drawing the attention of the Ministry of Magic and the Order of the Phoenix, only to come here and attack the Burrow.
Taking advantage of the Order members being away, were they? How despicable.
Harry's gaze hardened. But if you think you can do whatever you like just because the Order isn't here, you're sorely mistaken.
His figure flickered, and Harry appeared right beside Mrs. Weasley. It was actually only a few steps away, but Harry had used Apparition anyway. Don't ask. If you did, the answer was confidence!
And Harry certainly had grounds for that confidence. He appeared beside Mrs. Weasley without the slightest deviation, flicking his wand as a rapid string of incantations spilled from his mouth.
Eerie blue flames gushed from Harry's wand, enveloping him, Mrs. Weasley, Bill, and Pheobe. The spells the Death Eaters cast struck the flames, raising enormous waves of fire, but could not break through.
Fireshield Charm.
It was one of the few pieces of modern magic Harry had learned from Grindelwald.
It was not that Grindelwald was unwilling to teach Harry. It was simply that almost everything Grindelwald excelled at was dark magic, and Voldemort knew almost all the dark magic he knew.
Consequently, Harry, who had gained the memories contained in Voldemort's soul fragment, knew almost all of it too. There was therefore little Grindelwald could teach him.
There was even less to be said for ancient magic and ancient sorcery.
Even though Grindelwald was unquestionably a master in those fields, Harry, who possessed the legacies of two Hogwarts Founders, knew so much magic that Grindelwald could not