Concept-ual Enemy Edit
As an Ethereal Hybrid this monster takes many forms, it can theoretically even take over a Creatures of Shadow (immortal serial killers). The Channel Concept1 and the Twitter ThatPizza1 are both known to be run by it.
Joe Highman is one of two monster hunters that came into contact with Concept, The other being Greg. There is debate on what happpened and when, as time is moving abnormally for the two hunters.