Marco's vessel

This unnamed man was the vessel of the demon Marco in order for Marco to walk on earth and kill people who lost their soul to Amara. The man was killed along with Marco by Dean Winchester.

Background
At some unknown point this unnamed man was possessed by the demon Marco in order to kill people who have made deals with Amara. When Dean Winchester wants to kill Marco Sam Winchester stops him and tells him that he could just exorcise him in order to save Marco's vessel. However Sam notices that Marco was hot in the chest, hence his vessel would die either way. With that Sam lets Dean kill Marco and Dean stabs Marco with an Angel Blade, killing Marco and his vessel.