The music that plays around Tiamat is the same music that plays for the final boss of Keeper of the Lake, Sohr Khai, and Alphascape V2.0(O10). The tracks name is Primogenitor and only drops from Alphascape V2.0 but can be purchased from the market board from other players. All of the orchestrion rolls for the FFXV crossover event are songs from FFXV.