I have a feeling that (like the dad) Seungyeon's soul is occupying Je Ho's body. It would explain why Je Ho knew and talked like Seungyeon and how he knew something was off with Ha joon (ie. presuming who ever was in control of Hajoons body was dead by asking for how long).
Pretty good so far. It reminds me of Path of the Shaman, which I recommend you guys give a go if you liked this one.