It looks like Misceivous Heart gives non-attacking moves +1 priority. I'm thinking it's only +1 because someone claims that it doesn't give +1 priority so I think they were facing something slightly faster that used Quick Attack. If that's the case, Protect, Fake Out, Follow Me, etc. would still go before it. There's a chance it gives non attacking moves 1 higher priority, so things like Protect would have +4 priority and Trick Room would have -5. Someone should test to see if and Erufuun using Trick Room goes before a Deoxys using Trick Room.