Funnily enough, they are called a starter.
The person who starts a religion through the commandemnt of God is called a Prophet.
A person who starts an organization is called its founder.
A trigger Incident is basically what starts the story.
A mad person that starts with "man" could be called a "maniac."
an entrepreneur
Here it is in order "BLOOD" "BLOODSTAINED" "TRIGGER" "SLOWLY" "SLOWLY" "STARTS PULLING" Hope it help and it's my first time answering =)
starter person
Artisan
Could be buffoon.
Aviator
Entrepreneur?