Vento Aureo - Chapter 125 
A close quarter fight ensues between Bucciarati and Secco. As Oasis is more powerful than Sticky Fingers, Bucciarati is thrown into a shop window, breaking the glass. While he recovers, Secco remarks that something shines at the 3rd floor of the Colosseum; this is the reflection of a wheelchair-bound man's binocular.
Now certain that there's something to obtain here, Secco goes on to finish off Bucciarati. However, Bucciarati disappears into the ground. Secco hears him move toward the Colosseum, and figures that his opponent will need to breathe eventually thus revealing himself. That doesn't happen, to Secco's confusion.