When Deke wanders into Madam Chen's room located in her brothel, she morphs into her demon form while hiding and slits his throat before he can react to her. Hana enters the room some time later to see Madam Chen holding Deke's corpse. Madam Chen reveals her demon form to Hana and throws Deke's body off her balcony, which causes him to fall through her restaurant's glass ceiling and onto a spiked statue that splits his corpse's head right down the middle.
Glas finds his way into Hell and soon after periodically hears his name being moaned by a familiar voice and a shadowy figure of Deke walking in the distance. He follows the voice to an icy room filled with murky water, where the water joins together to form Deke's rotting torn in half head along with a bubbly mass covered in the faces of Deke's victims and arms with long black claws at the end. The demonic form of Deke tells Glas that his appearance was made to look more hideous every time he pulled the trigger on a victim. Glas expresses his apology, which angers Deke due to his belief that he is in Hell because Glas didn't cover all the angles on their ransom mission. Deke tells Glas that his eternity is about to start and is going to be horrifying.
Deke prepares to attack Glas but is halted when Glas shoots his form, which damages him and causes the souls of his former victims to fly out. Deke morphs back into water and tries to swallow Glas by dissolving the floating platforms holding him above the water. Glas shoots Deke's demonic form enough to cause it to revert to a harmless puddle of water. As Deke dissolves, he calls out Glas's name one last time, leaving only an eyeball that Glas picks up. Glas tells Deke to rest easy and that he'll make the ones responsible for his death pay for it. Glas puts Demon Deke's eye in a well bucket up above him that Hana later finds when she turns the crank lifting the bucket up. When picked up, the eyeball is called the Stone Eye, which is used for a puzzle later on.
Demon Deke is made up of a mass of murky water and the souls of Deke's victims on Earth. It takes the shape of Deke's head split down the middle from impalement. Its body is a writhing mass of faces of Deke's previous victims, and each appendage has long black spikes in place of fingers. He is very dangerous and can kill Glas instantly by drowing him in his watery mass.
When the battle begins, Glas will be on a thin platform made of three floating blocks with water surrounding him. Deke will start the battle solidified, so quickly shoot at him with a powerful weapon, preferably an Assault Rifle. Souls will fly out of Deke and he'll turn into liquid and move around the water really fast. Deke will cross over some platforms and dissolve them temporarily before they appear again. He can dissolve a platform even if Glas is standing on it, so try to anticipate which platform Deke will cross ahead of time. After Deke is wounded enough, more platforms appear, and he will start dissolving more platforms at a time and with greater speed. You need to keep dodging until he solidifies and blast him three times for the victory.