I was going to watch Ghost first, just because it would be my first SJS drama, then this and lastly IDID, but this was subbed first so I'm halfway through it and do I LOVE the action sequences. And I'll say Kang San is no Young Gye (CYHMH), but I'll have to get over it. *goes back to watching*
So Gaksital right now is his brother? Who is pretending (very badly) at being mentally challenged after being tortured.