Well, actually, it was a top-down design playing with the theme of werewolves.
Lesser and Greater Werewolves, the first two (in Legends and Homelands) tried to implement a sort of lycanthropy by weakening the enemy critters, but that didn't make much sense.
The next two, in Odyssey block I think (I do remember one called Treacherous Werewolf in probably Judgement) for some reason just turned on you, but didn't really infect anything.
So with this one, I had it actually infect stuff, but turning enemy critters into copies of the werewolf. Then, since they went mad with lycanthropy, they joined the originator's side.
The most fitting application of lycanthropy I've seen yet.
Of course, a vampire should have a similar ability, too, but perhaps taking control of the critter and making it into a zombie (ghoul) or vampire in addition to its critter type. It should be on combat damage, too, since a vampire bite can convert. The vampire doesn't need to suck *all* your blood to convert.