User blog comment:Bob the Wikipedian/A survey of Wesen using this wiki/@comment-1648698-20121014051032/@comment-2255188-20121015173109

Any time we learn something new about a Wesen (this happens all the time with Blutbaden and Grimms) your score for that Wesen will fall (or go up if you match the new attribute). If we learn about a new Wesen and your personality scores higher for that Wesen than the one you currently have, it'll change. As your score approaches a 100% match, there'll be less opportunity for it to shift to a different Wesen-- I see you're at 90% now, so it's going to be pretty stable now-- mine's been stable since it hit 80%.