I originally posted this suggestion on the steam forums a while back (9th of november 2017) however some friendly community members redirected me to this place since its more active. I’d like to hear some more feedback if at all possible so i get to know what you guys think and how to tweak it if necessary. 
The Usurper - New Neutral Class Idea
The Usurper
Unique Neutral - Social class.
Conversion immune.
Will not appear in games with an Evil King present at the start.
Win condition: Live long enough to become the new king.
Passives:
Dark Blood - You cannot vote for a new King but other peoples votes for you count twice.
Tyranny - When elected as King you will be revealed as a confirmed Evil King and cannot be accused of treason during the next 3 days. (Replaces Loyalty)
Day ability:
Royal Scandal - Prevent anyone with Royal blood from stepping forward this day as candidate for kingship. 1x Use only.
Night abilities:
Spy Network - Your spies make you seem not suspicious and Blue Dragon to all investigative classes except to the King. 4x Uses only.
Regicide - Attempt to kill the King this night. Cannot be blocked by the King’s guards ability. Whenever this ability doesnt target the King it wont lose its charge. (Think of redirection, occupation, possession etc.) 1x Use only.
Strategy:
The Usurper is a social class that needs to convince the council to elect him as King.
Using his Spy Network he can gain trust with investigative Blue Dragon classes.
The King however will not be affected by this ability when using Allies!.
Regicide is a great late game tool when there is no more knights and healers to protect the King. Once the King is dead using Royal Scandal the Usurper can increase his chances of being elected. This will however alert everyone that a Usurper is trying to claim the throne.
The new problem it creates:
The King (especially a neutral one) will want to eliminate a Usurper as soon as possible since he is the target. Blue Dragon will also be punished for electing a Usurper to the throne since they will be stuck with an Evil King that cannot be removed for the next 3 days hindering their win condition. The Unseen/Cult however might want to support the Usurper ensuring that at least no Good King is controlling the votes. The reward for finding and killing a Usurper for the Blue Dragon Faction is that they know through deduction that the original King is either Neutral or Blue Dragon but cannot be Evil.
Reminder: Once the Usurper gains the throne and becomes an Evil King he has already won the game. He does not need to help the Unseen/Cult to victory, its simply thematic and is in line with his Tyranny passive. However the Blue Dragon do need to get rid of the Evil King for their win condition. This increases the value of Nightshade poison of butlers slightly.
Side note: Regicide can only slay the king its not a standard killing ability. If you commit to regicide at night and for example hit a knight with it due to redirection nothing happens and you keep the charge on it.