Strongheart is imprisoned in the Prison of Agony. He has spent many years scraping the cement away from one of the stone blocks and has hidden the hole with a barrel (marked with SANTORY 1855). He has had his helmet and magical golden hammer confiscated from him by Venger. He escapes from the prison with the heroes and helps them in defeating Venger and liberating the other prisoners.
Strongheart is mentioned in the Power Is The Key story. Venger states that aeons ago he had a battle with the Dragon Master and Strongheart resulting in the Key of Power being lost to him when it fell into the Black Lake. Omitting time travel or talking about another similarly-named character, this would imply that Strongheart is ancient if the battle occurred "aeons ago".