My strat is now obsolete with removal of OE 
Use both your parties ASAP and hope to get jailed within first three nights to ensure you reach D4 without getting killed or converted.
If you don’t feel King has confirmed himself as Good, poison him as soon as D4 begins.
If he confirms himself during the day, let everyone know he needs heals because you poisoned him.
If by the end of the day it is still unclear what his faction his, whisper him at the very last second that you’ve poisoned him and that he should OE someone he believes to be the Mastermind.
I’ve had really great success with this strategy, I use it literally every single Butler game I play. You’d be surprised at how accurate Good Kings are at sniping Masterminds when you force their hand.
just gonna put this here…