After absorbing the blood from his surroundings, William descended to the ground and looked at Jasmine and Marcus, who stood there with bewildered expressions on their faces,he can understand why they are making that kind of faces afterall it was not a pleasant scene,he understood that this is the first time they have seen someone absorbing the blood from their foes,he simply replenished some of the energy,he is someone who don't rely on humans blood,he can eat like humans and could survive without any consumption of the human blood,but at the same time the vampire blood is good source to replenish some of the energy he lost during his slumber,it was merely a fraction but he didn't wanted to waste it.
