Origin
Little is known about Oliver. A chef and restauranteur from New York, he was married at least once in his life, and he and his now ex-wife had two daughters. At some point he opened his own restaurant.
Creation
Oliver was created by James Tynion IV, Ming Doyle, and Riley Rossmo. He made his first appearance in Constantine: The Hellblazer #1.
Major Story Arcs
The Hellblazer
Oliver encounters John Constantine by coincidence when the man wanders into his restaurant. The pair hit it off, but soon part ways when Constantine is called away. However, Oliver repeatedly runs into Constantine around the city, apparently completely coincidentally. They eventually enter a relationship, almost immediately after which Oliver is taken hostage by Papa Midnite in an effort to control Constantine. Constantine attempts to end their relationship, but Oliver refuses and pursues him, inadvertently allowing the demon Blythe to capture his children as part of a revenge plot against Constantine. When Constantine fails to rescue the children, Oliver angrily parts ways with him. He trades his soul to Blythe in exchange for his children, and is dragged to Hell, despite Constantine having just successfully bartered for their release.
Powers and Abilities
Oliver has no known superhuman powers or abilities. He is a normal human in above-average physical shape. He is a skilled chef and a competent business owner.