The Set of the Death Seraph is a vanitydeveloper set consisting of a robe, a garb and a helmet and a tail. It can be obtained from the Equipment Cube (Dan Yami). Dan's Demon Tail can also be obtained using the Key to the Heart with the character name "Dan" or "Dan Yami". This set was made for Dan Yami, the lead developer of the Shadows of Abaddon mod.
The Set of the Death Seraph also includes these items, which will drop in addition to the dev set: