Superboss last. I'm perfectly fine with receiving nothing at all for a superboss, because I fight the superboss for the challenge, not for the reward. If you can beat the superboss, you don't need to become any stronger, do you?

It's kinda funny actually, how I think XII botched it with the Wyrmhero Blade, but XII IZJS did it perfectly with the Trial Mode and unlocking "Weak Mode" (EXP gain disabled) for beating it.