noun
instigator
IN-stih-gay-ter/ˈɪnstɪɡeɪtər/
A person who starts or provokes an action or event.
The instigator hands another spectator a tomato and points toward the performer.

Etymology
Latin instigator meant “a stimulator,” someone who urges action. This makes an instigator the person who sets trouble in motion, including by encouraging others to act.
In context
you are both a moderator and an instigator meaning you will start the fires but you'll also put the fires out you will ask the questions to steer the conversation in the right direction
More examples
- The principal asks who was the instigator of the fight.
- Maya is the main instigator behind our neighborhood cleanup.
- The instigators of the walkout urge their coworkers to join.
Forms
instigator · instigators
instigate verb — To start or provoke an action.
instigation noun — The act of starting or provoking something.
Similar words
- initiator
- Starts an activity without necessarily provoking conflict or trouble.
- provocateur
- Deliberately provokes strong reactions, often for political purposes.
- ringleader
- Leads a group engaged in mischief or illegal activity.