Mayor - Townsfolk

If only 3 players live & no execution occurs, your team wins. If you die at night, another player might die instead.

Your ultimate goal is to survive until final three and be trusted enough by your team that they choose not to execute anyone, winning you the game. This is hard to achieve, but you can try hard claiming to one trusted player (the person killed first by the Demon is often a safe bet) and then claiming other roles to other people.
Because Demon kills on you can be redirected elsewhere, you can claim powerful roles and sink Demon kills that way. Beware though, that getting into a double claim this way may lead to your execution, and if the Demon tries to kill you more than once you will eventually die.
If you manage to get to final three, well done! Now you can use the trust you built with the player you claimed to early in the game to try and convince your team to go for the Mayor win.