Naruto would first be extremely confused by the rules of the Death Note. His understanding of power and its consequences is rooted in his ninja training and his own moral compass. The Death Note's rules, which seem so simple yet so deadly, would be completely foreign to him. He would question why anyone would create such a thing and would be very hesitant to even consider using it, as it goes against everything he stands for in his world of ninjas, friendship, and protecting the innocent.
She might react with caution at first. Given that Death Eaters are known for their cruelty, Hermione would be smart to be on her guard. She would likely start by gathering information about the escaped Death Eater, like his known abilities and any possible weaknesses.