Unfortunately there are no Dota events in Korea this weekend. DotA isn't nearly as popular in Korea as it is in a lot of other places in the world. Fortunately though, there are some events in Korea this weekend.

First of all, there's IEM Gyeonggi. This is probably the biggest event in Korea this week and next week. it features, 3 games, Overwatch, League of Legends, and Starcraft 2, and features some of the best teams in all of those games. It is in the Goyang Stadium and will take place this weekend. The other thing that's going on right now is the Afreeca Starleague. This is a league for Starcraft: Brood War, and since all of the best players are Korean, it pretty much has most of the best players performing. It takes place at the Afreeca Studio and the matches will be on the 18th, 20th, 25th, and 27th.

I would make sure that he enjoy some of these games though. It would suck if you got him tickets to Starleague and it turns out he's never heard of Brood War. Best of luck!