User blog comment:Mineko Charat Lucky/League and the Institute has nothing to do with League of Legends anymore(?)/@comment-15365593-20130815072332

Simply put, if they don't join the league, you don't get to play them. So one way or another, they have to.

Another note: There's no note on whether Lucian and Thresh (as well as Rengar and Kha'Zix) have ever clashed after their first battle. So what do you mean by letting his foe go away?