I didn't see a thread on this one. Here's partial guide,as I've completed a couple stages, but I forget what the first part was. I think it was find an item, but I can't be sure.
Step 1: I forget what this was. If someone posts below, I can update it.
Step 2: Complete 500 time missions. Rewards XP, an Epic Item & an Equipment Box.
Step 3: Complete 500 duels. Rewards XP, an Epic Item & an Equipment Box.