Slightly unrelated, but does anyone know how I might get the Shiva EX quest back? I have unlocked the arena, but accidentally abandoned the quest and I can't figure out where to pick it up. Urianger doesn't have it nor does the guy in Whitebrim who I remember having to talk to on the way to the Aethyrite.

Levi and Mog EX are required to unlock Ramuh EX. Ramuh EX is required to unlock Shiva EX is how the progression goes to contribute.