Sion's doppelganger is either known as Sion - Jet Black, or Black-Hooded Sion. He has his own signature theme song and outfit. He can be unlocked by successfully completing Survival Mode using any character; he's the last obstacle there. He can only be used in VS Mode and Survival Mode.
Black-Hooded Sion Saga[]
He only appeared in the third installment in the Bouncer tetralogy, originally a trilogy. He started as Sion's darkness inside of him manifested after he drank a Sapporo. This took Sion on top of one of the rooves at Dog Street, filling him with a sense of intrigue while he embraced his dark side and altered outfit! This gave him more prowess as he wiped out a number of street gangs night after night, till he showed up at the bar, Fate. As Boss was readjusting hours, Sion grew irritated as he wanted to take in all the hours, while also be the best and most dominant fighter in Edge! The dark spirit kept on feeding him vanity and overzealousness even when he fought Volt and backhanded Dominique. Although, once he saw his master in distress, the darkness manifested more to the point it caused intense pain while pushing it out of his body! The fission caused Jet Black to split and caused a few other murders, which resulted the real Sion being framed. He waited at the higher ledge of the alley and challenged Sion to a fight, in which Sion lost, but once Volt and Kou got involved, the pain was affected by the 2 Sions simultaneously! After the original was stunned, Jet Black snatched Dominique, and soared in a large dark mass carrying her to Mikado!
Later on, Gohan, using Piccolo's telepathy, spoke to Jet Black he must wait to win over his original before he should kill Dominique and make the original suffer! He agreed, and waited in the shadows at the executive floor. He also reanimated some fallen enemies such as the Rent-a-cops, robots, artificial dogs, Special Forces, and a few Air-Carrier pilots in order to hinder Sion from progressing.
By the time he finally made it, with the assistance by Gohan, he met up with Jet Black, and resumed their last fight imitating their moves. Even the Kamehameha Wave in which Jet Black used earlier to take out Sion, from remembering Ayame using it. Sion mastered his own technique which clashed with Jet Black's umbrakinesis. With the support from meditation, Wong and Kaldea, Sion's wave overpowered Jet Black's own after the explosion subsided, leaving him close to death. He was uncertain what he is as he should be the real Sion, though his original assured he is himself, his dark persona manifesting since tragedy struck and became an edgelord. He said he's no longer alone, and accepted his threat he'll always be a part of him.