TLDR and role description at the buttom.
The Pretender as a whole is a very well balanced and well designed role, in terms of the feel of the Pretender, the role fulfills its duty pretty well - you are someone who is not part of the royal family or the elite, doesn’t care who survives the coup that is going on at the high court as long as you get to be the ruler of it all when it ends.
At first you check the surroundings, kill political opponents (royals), and when you finally get the throne, you are in the spotlight, therefore fragile (with only 1 guard to protect you) and become extra careful at keeping your identity secret.
In terms of gameplay the Pretender is on paper, also doing it’s job very well, it is a very hard role to win with, but you got all the tools you need, you can kill king by yourself, kill royals who can challenge you to the throne and you have perfect kit to disguise as Princess -> on paper it is a very hard role to play, and win with, just like Neuts should be (and not all roles needs to be at the same difficulty, nobody here is playing on tournaments and have money on the line).
The problem starts with that the Pretender can easily decide that it wants to be an unconvertable BD Princess.
I think the solution to the problem is not as easy as it looks, by making Pretender not being able to win with BD, you are creating a situation where MM, Princess, and Pretender have the same ability, same claimspace, but 2 of them are evil and the 3rd only spawns in 1 of 2-3 games, this will quickly result in a situation where Princess claim would be the same thing as a Knight claim (instant exe).
My solution would be to make Pretender not be able to win with BD, and rework MM or Pretender in a way that their abilities are not identical to Princess.
My suggestion - while making the Pretender unable to win with BD, let it choose which role it wants to imitate at the beginning of the game. (this will lift off some of suspicion against Princess claims, and allow the Pretender to be elusive as it was always meant to be)
Passive: Blood Test - you will be notified if the target of any of your abilities is Royal.
Passive: Corrupted Path - You will need to decide which Royal Family member to Imitate
Princess - Same as now.
Drunk - Day abilities - Reverse Vote + Silence, Night abilities - Debauchery + King Slayer.
Noble - Day abilities - Reverse Vote + Twin, Night abilities - Gossip + King Slayer.
Edit: King Slayer kills will appear as a Assassin or CL kills (depends on the game) to Phys’ exhume, otherwise it would be impossible for the Pretender to kill king and not get exed by BD.