This strategy takes a high level of skill, specifically reading into people in shorts amount of time. Forum Mafia will help you improve here.
So, Rainbow. The mode of chaos, where most of the time, there are no lynches, or everything is random. There aren't survivor claims D1, but a bunch of them mid-day or in Jail. What do you do with all this randomness?
Here's what you do:
You rely on claims and reads to know who you want to kill, or what you want to do.
Here are the things you want to do as each faction/role:
Mafia - Main Ally: Witch Night Kill Target: Amnesiac Lynch Target: Arsonists
Witch - These guys can stop the evil Serial Killers from Killing your Mafioso, or Arsonists from killing you, and only has a 50% chance to affect you'll be affected
Amnesiac - Unless the Any is Mafia, Amnesiacs likely will join the Arsonists or Serial Killers. They cannot become you, and they're not night immune, so target them
Arsonists - Sure, the SKs can kill one of you, but you can try to trick them later in the game. Arsonist can kill both of you, and are the ultimate threat of the game, able to kill everyone.
Arsonists - Main Ally: Other Arsonists Night Kill Target: Town Lynch Target: Mafia
Arsonists - The best team you have is your own. You can kill anyone, and as soon as someone is doused, they're out for you. Arsonists can collaborate through death notes on when to ignite, who to douse, etc.
Town - They're your bane. If either of them still can use their ability in an endgame, they win. The jailor can kill you early, and the Veteran just wants to save themselves from attacks, not mass-kill. So get them and get out.
Mafia - If you're not killing Mafia at night, lynch one of them. An informed group can be very powerful towards the endgame, and if it's 2v1 or 3v2, you're doomed. Also, Survivors and Witches will likely side with them.
Survivors - Get your name out there. The longer you wait, the less believable your claim is. Keep reminding people, and they won't want to hurt an ally.
Town - Main Ally: Survivors Night Kill Target: Serial Killers Lynch Target: Mafia
Survivors - Survivors will probably go with the side that wins the least in the endgame, so team up with them. The Mafia could work too, as you can easily win in a 1v1, and Arsonist if you aren't doused. Just find a place to fit
Serial Killers - They make the most nightly kills of any faction, and the longer they live, the more likely you are to die. Also, SKs in Jail :\
Mafia - You need one lynched in order to win in the endgame with them, so think long-term.
Note: As soon as you're doused, change all targets to Arsonists, as you can die at any time now.
Amnesiacs - You have 2 tactics:
Be peaceful - Remember Witch or Survivor, claim you're that person, and anyone messing with you from there on, quote this:
Spoiler:
Steal the win - If an Arsonist dies night 2 or 3 with something from 10 or less people alive, become an Arsonist. The other Amnesiac likely will too, and you will have a power group. If they aren't dying, become Serial Killer. You still have an effective faction that can take the majority and kill the town and a Mafioso.
Serial Killers - Main Ally: Survivors Night Kill Target: Town Lynch Target: Arsonists
Survivors - They have vests, they won't be that afraid of you, especially if you vow you won't attack them. Witches will likely mess up your killing flow to protect themselves, but they work when it comes to voting.
Town - You have a Veteran, trying to save himself from being shot, and can 1v1 you in the endgame, which is a gamble. You also have a Jailor that can kill you literally or passively, through wills and you will likely be lynched for some random reason :\ So, yeah. Kill them off as fast as you can, but be cautious of alerts.
Arsonists - They're the only faction bigger than you. They can kill everyone, including you, they have the same numbers as you, is in your case in the endgame, is basically you but stronger in this setup. You can get an easy lynch out of them as they're prime targets to kill. It's all a long-term plan that will help in the endgame.
Witches - Claim, confirm yourself on a Survivor claimer, and do what survivors do, remind people constantly. You can convince Jailors not to execute you because you aren't the primary kill. I've had good games where I sided with the Jailor, Veteran, and Godfather, and lasted for a long time working with the town, ending with a Mafia win. Anyone killing you is basically what I said for the first Amnesiac tactic.
Anys:
Jester/Executioner - What people lynch on varies between games, so that can change. However, Executioners can claim on stand, and people will probably lynch the town, or if you want to be subtle, just put one vote on someone. For Jesters, become an annoyance that people just dislike and want out of the game. Don't spam, because that's rulebreaking, but being annoying all varies on how you feel, Ex. Name, Spoiling a Movie, Unpopular opinion on Politics/games/movies etc.
Werewolf - Main Ally: Witches Night Kill Target: Town Lynch Target: Arsonists
Witches - If you communicate, you won't be threats to each other, and to be safe they can control you every other night. Survivors will probably fear you because of your killing ability
Town - Veterans tend to get attention, and if you attack them when they aren't alerting, you can get a bunch of kills in, but you have to read when they're alerting correctly. Also, endgame + alert = bad time. Jailors can out you like Serial Killers, and they can getcha in the endgame. Also, you probably want to avoid attention unless you want to stay home for some reason.
Arsonists - 2 people, more kills, can kill you easily, you don't want to stay home, you probably want to kill them before they douse you, because you're your own only hope, and you can't do much.
Vampire - Try to bite the town for less threats and Amnesiacs so you don't have a big role against you. You can try to persuade the jailor to get bitten if you want. Survivors and Witches probably will side with you for this rare occurrence. Everyone who you can't bite though, except for witches, are lynch targets, as they're in a faction that can kill you, or jailed :\