If one was to be evil would that one naturally share that thought? It is true that often times Evil is confused with good within the very eye that be holds it. Further more, there is no definitive "right" granted to any whom partake in the light or dark other then the typical perception of peers which may or may not be biased.
Regardless, You may have "alignments" at HHSR though its not necessary to "say" or boat them, simply go along with the flow of your characters naturally.
As far as your main question, iv been trying to get a few monsters and otherwise "shifty" npcs to come to the school, but alas none seem to have time for it at the given time. Perhaps soon that will change. If you have friends of friends who want to be creatures or what not send em my way and we'll see what can be worked out.