I'm terrified of him.
It's related to blood transfusions. Based on my unfortunate experience as a hospital patient, blood transfusions are typically performed when:
a) the hemoglobin level drops below 80 g/L;
b) the volume of blood lost exceeds approximately 1 liter.
People with anemia often experience weakness, dizziness, drowsiness, and shortness of breath during physical activities, accompanied by a black vignette around the eyes due to a lack of oxygen in the blood, resulting in reduced visual acuity. Some people may be in worse shape, and they may faint. These people often get sick.
In the manga, he doesn't seem to be in any particular bad shape, and he seems to be quite energetic. Each bag contains approximately 200 ml of blood, so he's taking in about 400 ml. Each bag is emptied within 15± minutes. Throughout the entire scene, not a single bag has been emptied, indicating that his hemoglobin levels and blood volume have not been replenished. In addition, he walks around with a 5 kg IV drip, holding his hand where the transfusion is taking place. As far as I'm concerned, it's painful when your hand is filled with liquid and you have a needle in your elbow.
Sorry for being so realistic, but this person is a monster.