Adele is a homunculus and part of one of Huey Laforet's groups (Lamia). The guy in the background with the bandanna and the glasses (Tim, AKA Tock Jefferson, Tick's brother) is the leader of Lamia. They kidnapped Dallas from the river, too.
They show up to offer Jacuzzi and friends partial immortality if they join the Laforet cause, and demonstrate said immortality by killing Dallas (the guy on the ground).
Christopher is also a Laforet-created homunculus part of Lamia. He ditches the Laforets after Ricardo Russo saves him from a mortal wound that Claire inflicted on him.