I'm reading the story after a long time and I'm noticing interesting things.
1) It got the protagonist's email address after having chatted with him on his website or something like that (Hacking or Clairvoyance).
2) Hacked the protagonist's website (definitely Hacking).
3) Somehow it found the protagonist's house (Clairvoyance).
4) It entered the protagonist's house and even climbed into his bed without waking him up (Stealth Mastery).
5) It causes its victims to not feel pain after ripping out their jaw (Pain Manipulation).
6) In addition to driving its victims crazy, it transforms them into new "Funnymouths" (Corruption and Madness Manipulation).
Edit: It should also be 9-C considering that in addition to tearing off the jaws it breaks them,
which should scale it to 375 Joules.