Brotherhood: Sauron

For reasons that have never been explained, the pteranodon bites somehow changed Karl, apparently altering his genetic structure. Karl discovered that he needed to drain life energy from other living beings to survive. His first unintentional victim was his dog Jager, whom he drained of energy simply by touching him. Karl kept his condition a secret, even after he found himself forced to drain energy from other human beings. However, he killed none of them, merely leaving them temporarily weakened.

As Karl grew older, he fell in love with Tanya, but the stern Dr. Anderssen refused to let her marry Karl because of his lack of financial means. So Karl Lykos set off for medical school, vowing to become wealthy so he could marry Tanya. Lykos became a hypnotherapist, but his need for life energy increased as he became an adult. Hence, he constructed devices through which he could drain his patients' life energies into himself.