Olympus Dungeon

2 questions regarding this dungeon:

1. Is it worth it grinding it out for all your school specific gear? I'm like 10-11 attempts deep and only got the robe. Ik after beating it 35 times you can craft the gear but is it that much better than something I can get at the Bazaar?

2. I've heard about this Alpha & Omega ring from some secret boss. Can someone explain what that is, how to get it, and if it's worth getting?