Granted, Entropy 4 can just give someone a disease, so Jesse is overcomplicating the matter and I really don't think this oculd be anything but Vulgar Magic, but....
World of Darkness is a setting that includes Mage: The Ascension which OP is referencing. (MTAs)
The same publisher released a later gameline now referred to as Chronicles of Darkness which includes Mage: The Awakening (MTAw) with a similar dynamic magic system.