happened to me by accident. discovered that you can return to Henesys using a weird interaction with Spinel being in Amoria. Try out the following path -> any map with Spinel and FM (Ludi , Perion, etc). -> Lushan -> FM -> Amoria-> Lushan again (using Spinel) -> Amoria (talk to spinel) -> Thomas swift (Fm) -> Lushan -> Spinel (will send you to amoria) -> Thomas swift. After following the mentioned path you're now in Henesys . i think this is also applicable to the other Spinel maps with fm in them (showa etc).
After a bit of self testing , it works from anymap with a FM. looks like the trigger is going to the same spinel map twice in a row . (fm -> Amoria (Spinel) -> Lushan -> fm -> Amoria (Spinel)-> Lushan ). trying to retrace from this point will return you to Henesys instead of your original location.