5. Player roles are revealed upon their death/execution until only 10 participants remain in the city. If there are 10 or fewer, all roles remain hidden. Exception: a serial killer's bloody murder or the doctor's serum.
Initially, there were 12-4-1=7 people in the city. What's the point of this interpretation?
And why would anyone kill anyone at all? Simply because those are the rules of the game.
You were more likely to kill Imaris because you don't care who you kill.

Барон "Vampires"
Отдай свои прошлые сны,
В сомненьях себя обрети,
В бешеном танце душа кружится!
Не думай, что будет потом,
Здесь и сейчас мы живем,
Стань хоть на миг сам собой, слышишь!