liberator
noun
[ ˈlɪbəreɪtə ]
• a person who liberates a person or place from imprisonment or oppression.
• "they were seen as liberators"
Similar:
rescuer,
saviour,
deliverer,
freer,
emancipator,
messiah,
champion,
knight in shining armour,
Good Samaritan,
manumitter,
