I fought mostly humans. I chose my enemies based on my ability to reset them later, and as forced food sources. I did fight Vamps but only after it appeared my 4 declared enemies wasn't working. I fought at least 3 Vamps, 2 aliens, a ghost, and 7 different regular age ranging from young adult to elder. The numbers could be higher. I was in well north of 30 fights before I gave up. This isn't my first rodeo with this aspiration but it was the only time I had an issue with it. I know it was a bug.