Well you know right, there is no news or any information since start regarding Jiwoo's father. Only Jiwoo's mother was shown and according to his mother Jiwoo grew up as normal boy unaware of the awakener thing and that she herself kept him out of that while working in an advanced pharmaceutical company. So who knows if Jiwoo's father is someone from Patrick family. It's just my hunch, nothing else.
This very well could be a possibility
Jiwoo's hair colour match with his mom, what if she's is related to patrick family because they all have same hair colour.
Another big possibility..... Right....
Ian looks like Jiwoo on this chapter lolol cutie what if they're the real brothers here ε=ε=(ノ≧∇≦)ノ