Even though it would never happen as they wouldn't put this much time into a limited event like Sega does with PSO2's content, an actually difficult 8-person trial in the vein of a Primal fight against Dark Falz, Olga Flow, or Saint-Milion/Kondrieu/Shambertin would be fantastic. Episode 1 and 2 version of Falz in particular would be an interesting fight with the second half taking place on that ring-like arena, I could see that working with FFXIV's combat system very well.