Vindicator (noun)

1. A person who defends or upholds the rights of another person or cause; a defender; an advocate.
2. A person who takes revenge for a wrong or an injury.

Origin:

The word "vindicator" is from the latin "vindicare" which means to avenge, to defend, to claim, or to set free.

Examples:

1. He was seen as the vindicator of the oppressed.
2. She was a fierce vindicator of women's rights.
3. The lawyer acted as vindicator for the falsely accused.
4. The soldier was a vindicator of freedom and democracy.
5. The detective was a vindicator of justice and would not rest until the perpetrator was brought to justice.