Just wanted to look at the forums and I still feel wronged. Shioon was a newbie at season 1, he was crippled but kinda badass in season 2. Now that he's mostly healed, stronger than ever, has great backing and a new resolve/goal but he gets a backseat? WTF!!!???? F*** you authors.....
It's not brain surgery. If I was the author, I'd introduce a junior rookie sister of Kang Sera tag along Shioon at the school. Through her eyes, we'd remember what kind guy Shioon was (and what he became). This new loli would have conversations with Kang Sera to help us fill up the time-gap and recent happenings in Murim. In 5-10 chapters we'd be re-introduced to the series.
On the other hand, Shioon would gather the 'new' characters from season 2 and form his own team to go after Kaiser (maybe even coordinate with the government). After all, he's not the real head of the Sunwoo clan and he'd have to use his own means. He'd start beat up Kaiser's minions save Sosul and GMR from his clutches and assert his dominance in Murim.