Most Korean IGLs are moderately disciplined/moderately aggressive, standard style with strong micromanagement, and FNS treats them like the back of his hand and knows everything they're going to do. He owns them.
On the other hand, he is a bit weak against extreme aggro styles like BLG and PRX. (Interestingly, other NA IGLs like Valyn and johnqt are very strong against Asian quick attack strats) If a Korean team beats him, it will be NS.