General synonyms:
* Released
* Freed
* Loosed
* Set free
* Let loose
* Liberated
More specific synonyms:
* For anger/power: Unbound, unleashed, erupted, exploded, erupted
* For animals: Let out, turned loose, set loose, released, liberated
* For creativity/energy: Uncorked, unleashed, released, let flow, liberated
Figurative synonyms:
* For an unstoppable force: Unleashed, unleashed, unleashed, unleashed, unleashed
* For great potential: Unleashed, unleashed, unleashed, unleashed, unleashed
The best word will depend on the specific situation.