Af and Hemah is a relic that can be found in The Darkness II. It's a pair of sapolas created from Af and Hemah, two angels of death bound by chains of fire and shadow in the seventh level of heaven.
When the Angelus came to God for a weapon against the Darkness, God reforged Af and Hemah into blades. It is said that Af and Hemah are inseparable, as trying to take only one of them will cause the blade to slip out of the wielder's hand or the wielder to drop dead from a stroke.
The relic is found in Hellgate Field after exiting the long tunnel leading to the other part of the amusement park. It's laying on the right side.