Have you notice, in the latest chapter (ch677), there is a new broker:
Is-he a sort of disco moria or something. even if i'm a Moria fan, i hope he isn't.
But to me, Moria'll return. According to Doflamingo, when he attacks him, he disappears into the void.Maybe this was makes by his devil fruit? Or Absalom touch him and made him invisible with his ability.
If he returns, i see an alliance with the strawhats, and other pirate (maybe Drake) for takes a revenge of Kaidou.
A second theory: he makes an alliance with Dofla: who said to the gouvernment he escapes, but dofla let him go for some reasons we discover lately.
What are your theories about him?