Here are some options:
Descriptive Phrases:
* An outreach speaker
* A dynamic speaker
* A charismatic speaker
* An engaging speaker
* A speaker who connects with the audience
* A speaker who inspires action
* A speaker with a powerful presence
Words with a broader meaning:
* Advocate: Someone who publicly supports or recommends a particular cause or policy.
* Activist: A person who campaigns to bring about political or social change.
* Ambassador: A person who acts as a representative or promoter of a particular cause or organization.
Ultimately, the best word or phrase will depend on the specific context and the speaker's actions.