Ok, so technically these are all “almost worst-case scenarios”. I do have the rule that “on a scale of 1-10 nothing is ever a 10, because it can ALWAYS get worse”. Thus the true absolute worst case scenario for everyone involves being tortured just to the point that you never lose consciousness but far beyond your ability to cope or adapt to the pain, out through the heat death of the universe and includes the obliteration of everyone and everything else. But hey, most likely that won’t happen. So think of all these possibilities as way better than that.
Remembering that the theme of the game is not “we’re evil muhaha” but rather a combination of crime-drama with a hint of “please don’t let them find out my secret” is a tricky balance. So to help with that, here is why everyone is trying to keep their monstrous nature a secret, because this is what you are afraid will happen if the authorities learn everything about your character that you know.
Jacques D’Lantignan, the Werepanther: As a lycanthrope Jacques would be burned at the stake without trial.
The Bane Sidhe: For reasons known only to her, if servants of LaWarre learned her secrets, she would have her mind shredded to extract the information, and be turned into an undead slave. A fate worse than death. If the royal family found out when she joined the Ministry and what her original job was she would be executed.
The Red Headed Stepchild: If her vampire pursuer finds her she would be raped and abused then eventually abandoned and forgotten probably while locked in a coffin she isn’t strong enough to open to suffer for millennia from starvation and insanity and isolation. If the wrong people find out where she is from, even though she has permission to be in Kentarre, she could be murdered, and at the least would be subject to extreme discrimination, possibly violent.
The Cursed Blade: If the knights find out that it is fully sentient and not only animating the corpse of one of their own but also holding a shard of his soul from the afterlife, they would permanently kill the knight’s body (this is likely to banish the poor man’s soul to the abyss) and use rituals to cripple the sword’s intellect then lock it into a vault for a century or two before giving it to some other person who may or may not be worthy. Think Charlie from Flowers for Algernon, where he knew he was dumb and used to be smart, but the sword cannot commit suicide and will never die, just be enslaved forever with the knowledge that it failed and that it is now less than it used to be.
The Shapeshifter: If he actually does give into his rage instead of triumphing over it, and especially if he ever pulls an Annakin and wipes out a whole village of innocent hunters because of what the guilty ones did, then he would be executed. If the wrong person finds out he is a changeling he could be banished from the order for being an imposter (even though he isn’t) or killed outright. In a true worst-case scenario, someone might mistake him for a child of the Monster Lord of Faseloo, and that would involve being tortured to death using the principle that if he’s innocent he’ll die without breaking and if he’s guilty he’ll break.
The Hag: As a murderous creature and a loyal citizen of the Monster Lord from Gallia she would be burned at the stake without trial.
The Blaspheme: If he completes his quest and kills the primordial who granted his power he will become a level 1 commoner without magic, probably slip into existential despair and end up one of those starving people who don’t have enough will to live to brush a fly off of their own eyeballs or even blink. If he is correct about who the primordial is, then completing the quest will also cause a blight that might result in his whole province becoming a wasteland of barren rock where no life will grow. If he fails his quest then he will lose his championship and be banished from all the lands loyal to the Royal Family. As an ex champion, the hunters and servants of the monsters will both hunt him down and try to kill him. If the wrong priest or champion finds out where he gets his magic powers, they might respond even worse than his lord and just kill him outright.
All in all, I think that the werepanther and hag probably have it best.