Orchestrion for Seat of Sacrifice song?

Thanks for the help!

Are "Invincble" (Hades) and "To The Edge" (WoL) not the songs you're looking for? I'm only asking because both of those are available by using drops from the Extremes... But its obviously possible you're thinking of a different song playing during the trials.

Pardon my ignorance but is it not To The Edge? The faded orchestrion roll that drops from the ex version?

Trial orchestrion rolls always come from the extreme fight. It's no different this time, though you should be able to buy in on the market if you don't wanna bother with it.