But similar to wandless magic, Hermione knew the ritual magic needed to be better harnessed; controlled to maim and not kill. Their emotions,  her emotions , would have to be kept in check. Malfoy said she could control it. He didn’t want her to, but if their lives depended on staying undercover, remaining in the shadows until it was time to strike–then they had to reign in the deadliness of their magic. Maybe this was the reason he had requested she even retrieve the wand of Abraxas–they had to use the Blood Magic, not let it use them. There had to be other incantations, additional spells in the ritual book that required a wand. 