The roles they play, are they like real historical figures???

Yes! King Danjong overthrown by his own uncle. I always cried whenever i read stories about Danjong. If you're interested about King Danjong, there's a very good movie called "The King's Warden" about him. I cried buckets watching it :')) funfact the movie become biggest Saeguk movie with 16M ticket sold in Korea

Thanks for the info!