After beating Titan and getting new jobs including Warlock and Shaman. None of the NES GameFAQS walkthroughs give me the valid info to return to Dorga's House, and the walkthroughs on YouTube seem to skip this part altogether...?

I am supposed to fight Dorga and Unne now, but how do I get back? I keep getting blasted away by an invisible wall whenever I use the Invincible airship or any character by the entrance towards the house.