Quote Originally Posted by Remon View Post
On the right track but no.

And HC...I never would have guessed that -__-
The 'hidden deep below' part made me think of the Onion Knight, but it's gotta be Rikku's God Hand then:

Reach it from above - get it via the airship.
With the power of the undying in your hand. - You receive the cloudy mirror from that dead summoner.
Unlimited riches - the weapon has gillionaire.