Diablo

Diablo, also known as D, was one of the members of a Criminal Heisting Gang in his past life, with Jimmy and Ace. During Fadious' Search he was abducted by Fadious along with Jimmy, as they were both turned into Subjects.

Past Life (Criminal)
Diablo wears a similar outfit to what he does in the Present, that being a tall collar black leather jacket and dark blue jeans, he doesn't have his horns, red skin or orange eyes, but he still has his good looks.

The Facility (Subject)
Diablo is first seen wearing the Subject jumpsuit when he chases after Cammy.

Present (Temple Member)
Diablo wears the same outfit he did back when he was a criminal.

Demon's Abilities
Diablo possesses all the powers of a high ranking Demon, being able to control Fire, Hellfire and even The Black Flame, but he refuses to use this power even if it costs him his life.

Volcanic Fist
Diablo's right hand has been replaced with a volcanic fist capable of delivering powerful explosive blows as well as hurl burning hot lava at foes.

Diablo mainly uses brute force over his other abilities as he would rather feel the impact of him hitting a foe than simply burning them from afar.

Personality
Diablo is a jackass.

Ideals
Eat ice-cream flavoured potato chips. This has been completed, now Diablo is forever happy.

Part 1
Diablo isn't introduced as a good character at first, as he is first ever seen chasing after Cammy trying to kill her. Only after when he has a change of heart does he decide to stick with Cammy and the others.

Part 2
During Part 2, Diablo and the rest of the Original Gang go missing. Due to the Player's Radio Hearts gaining a physical form in this Reality (gAME Reality). Later on in the Part, Sebastian assists 5th in bringing the Original Gang back.

Part 3
Part 3 doesn't involve Diablo as an incredibly important character, but he does make his appearance.

Part 4
Part 4 does have Diablo present, but not as a main focus. The focus was more around The Guardian Era and what it brought to the Universe, Guardians.

Part 5
Diablo does show himself in Part 5 as well as the rest of the Original Gang during the fight with Him, even being one of the first people to place his hand above the Player's hands to assist in helping revive Celestial.

Story 2 History
Soon to be added.

Trivia

 * Diablo was the first to ever get a girlfriend (Christine) out of all the Temple Members.
 * Diablo's favourite food is ice cream flavoured chips.
 * Diablo's character on MK (Which was modded by Percy) was made to be able to defeat every other character with ease.
 * It is unknown how Diablo was actually transformed by a Demon from Fadious, but from what he can tell, there's no downsides. Therefore he's fine with never learning how his transformation happened.