In the Manga, the President of the United States was modeled after than-Current President Barack Obama; in the Anime, they choose to model the President after Robert Downey Jr's Tony Stark from the Marvel Cinematic Universe.
Many episodes cover 3-4 chapters of the manhwa due to time constrains with the number of episodes and where the season had to finish resulting is some cuts and changes from the source material.
One of Han Dai-Wi's moves is called "the Black Tortoise". Coincidentally, Crunchyroll's previous Produced Anime, Tower of God, features a character who nickname's the Series Main Character Bam "Black Turtle."
Based on the Korean Webtoon of the same name.