Revenant

Revenants (レブナント Rebunanto) are a miserable race of human beings whose souls are incapable of separating from their bodies after death in "Highschool DxD: Of Kings and Pawns."

Summary
Revenants are a more recent race of creatures, being an unexpected result of the numerous bugs in God of the Bible's system after his death. Revenants are created when the system fails to register a human being as dead, causing them to be stuck in their bodies for all eternity. Life as a Revenant is believed to be exciting as getting a chance to live life once more is quite a gift to a human. This gift quickly goes south once decomposition sets in. Following this, Revenants are attacked by other humans; afraid of seeing a walking corpse primarily as a result of pop-culture zombies. The fate of most Revenants winds up being an eternal damnation residing within scattered and destroyed remains. Both Devils and Angels have been making an effort in escorting Revenants to either Heaven or the Underworld, but often find the Revenants far too late. On top of this, Revenants, despite once being human, are incapable of wielding Sacred Gears due to their glitched existence. There are sparse cases in which a Revenant is retrieved by Angels or Devils before they are destroyed; within those cases lie nigh-infinite potential as Revenants are considered to be immortal in most cases. In order to combat the crippling decomposition that plagues Revenants, Angels and Devils imbue them with magic so that they can live without worry of becoming to decomposed to even move. Despite living such a pitiful existence, Revenants hold more variants than most other races in existence. Being able to live long after skeletonization, Revenants have a whole new world of opportunities open for them if they manage to be escorted by either an Angel or a Devil. The most prominent and powerful type of Revenant, however, are Liches.