Diavolo (ディアボロ Diaboro) is the main antagonist of Part 5.

He is the boss of Passione and the father of Trish Una. He commands Team Bucciarati to bring her to him whilst keeping her safe from the traitorous Squadra Esecuzioni.

Diavolo is secretly the alternate personality of Vinegar Doppio, and is a Stand User who wields King Crimson in battle.‎

Diavolo is a tall man with a lean and semi-muscular build. He has long hair, leopard-patterned with various spots, parted in a zig-zagging manner; the bangs of which are propped and parted slightly to the side. The rest of his hair is cut straight across at his shoulders. His shirt, hidden under Doppio’s sweater, appears to be made of complex mesh-wiring: it covers his shoulders and torso but down his back and abdomen are linked circles that are tucked under his belt, which in the back end in two~three long “coat tails”. On his arms are floral sleeve tattoos leading down to a pair of gold wristbands. He also shares a pair of studded pants and seemingly sock-less loafers with Doppio.