Ikaris was tempted to transfer the resulting Blood Energy into the corresponding Storage Ring, then drink some more human blood, repeating the routine until it was full, but Magnus talked him out of it.
"You've already drunk a lot of blood today." The Vampire stated flatly. "Your Soul Strength and Self-Control Spark prevent you from experiencing any psychological symptoms, but if you continue your body will be exposed to withdrawal symptoms. You will then be required to drink as many gallons of blood if not more to relieve them each time they occur. For your own good, I suggest you keep your intake to a minimum for the next few days, even if it means staying hungry a little longer than necessary to get your body used to spacing out its meals.
"You will need two Sparks for this: Blood Fasting and Stamina/Blood Energy Conversion."