Hi everyone.
I have some inputs on witch. Be warned, I am a little biased; I have never won a game with witch before despite playing the role many, many times.
Witch wins if town loses and witch is STILL ALIVE. This actually means the witch has to be alive when the MAFIA wins (or SK, I believe). As a support for the evil roles, the witch is highly effective; she can feed false information to towners or simply disable key roles similar to the consort. The issue here is that the mafia/SK can kill the witch, which frustrates me to no ends. Different from a survivor who can just claim from Day 1, the witch cannot do this for simple reasons. The witch also cannot kill, unlike SK/arsonist, to eliminate any targets you think is a threat to you.
My opinion is that the key to witch is to be able to determine the roles of the towners and use them effectively, or alternatively find the mafia/SK, pm them, and make sure they don't target the witch. Currently, the witch has to do two of the above while avoiding getting detected by towners in order to survive. This is extremely hard. Unless you are brilliant, the information you get as a witch derives from the public chat. Thus, if you know what someone is, EVERYONE KNOWS. For example if a doctor is known, it won't actually help the witch... because he is likely dead next round by the combination of mafia and SK.
Detecting doctors as witch is almost hopeless. Witch cannot gather intel, so the best scenario for the witch to get a doctor is:
1. a doctor is publicly known;
2. the mafia cannot target the doctor.
This is pretty hard. The only way this can happen is that a doctor is put on trial for suspicion of being an SK, but there is another doctor who can heal this doctor such that he won't be immediately killed by the mafia. Furthermore, the witch also has to take the chance that he might be an SK.
Detecting mafia or other killing roles is also hard, although this one depends on luck a bit more. Every night you can randomly control someone (A) and force him to act on someone else (B). When B dies, you can reasonably deduce that A is likely to be a killing role, unless 1. B was killed by someone else; or 2. B got bussed, in both scenarios you will lose the game if you pm A.
Furthermore, there is no guarantee pms can be used in the game, as this depends on game setting. Even if it can be used, because pms are public, it will draw suspicion to the witch as well as her allies.
I think perhaps one/some of the following changes will improve the witch to the level that it is playable. Currently I think it's much harder to win as witch than as SK or arsonist.
1. Regardless of game settings, allow the witch to send anonymous pm to anonymous receivers;
2. Night immunity as an option;
3. Can win without surviving until the end, perhaps with less rewards;
4. Investigator cannot detect the difference between survivor and witch;
5. When controlling a sheriff, investigator, or consigliere, the witch can learn the intel the victim gathered.