I have a theory about Daechwita and I tried to back it up with things. here goes nothing I guess.
1) At first I thought that mv was heavily referenced from the movie masquerade + there was mentioned king Gwanghae.

2) But the gun and sudden modern elements wouldn’t let me breathe so I had the thought. What if this is not the false/true king thing but reincarnations? because Gwanghae was known to be despot but now, he`s not considered as such, history changed him – gave him another chance?

3) but he`s still one of the bad guys. For starters, he was not a king, he was the prince that`s why the dragon on this robe as 4 toes. he acted as the de facto ruler of the Joseon Dynasty.
let’s go frame by frame and forget about actual Gwanhae and look at him as a metaphor.

4)we start with Yoongi in the palace. From what we see the palace is dark and empty, with no servants no court around. He`s all alone and quite okay with it. Then he goes outside and we see dead people with wood boxes next to them, which we later find that it`s for their heads.

5) He has all the symbolism from the Joseon Dynasty, the earrings, the hanbok, hairstyle, the 4 toed dragons. now this situation is the most typical representation of a “mad king”. He has a scar, weird collection, and all.

6) then we see black-haired Yoongi and a Butcher. Let's stay here or a while – in Korean history there were people called The Baekjeong– they were practically nomads. With no rights and during Joseon Dynasty used as butchers and executioners. We see them twice.

7) First in the market and second when he`s dragging black haired Yoongi in the palace where he hands him the gun. That gun is 19th-century percussion cap pistol, in which time Baekjeong finally got their rights as citizens. (telling this very shortly there is a lot of history )

8) if we follow the black-haired Yoongi, we`ll see that butchers actually know him, they have eye contact and all. Then we see that he changed his clothes, which magically appeared in there and now he`s surrounded by his people, his crew.

9) Now this is the first difference from the “blond king”! he`s not alone.
then the girl hands him the keys which are already in the box FROM that era. Those keys have a keychain, jade talisman with cranes.

10)Redcrowned crane in Koreais called Durumi and is considered as a symbol of longevity, purity, peace. Jade was a royal stone. Blond yoongis earrings look like they have the same stones, it was a status symbol for the royal family due to its symbolism of good health and fortune.

11)But what are these clothes,an old-looking car from 2006?+ we can clearly see that these 2 know each other, the triumph in the king`s face when butcher brings tied Yoongi is clear.+ they smirk at each other when Yoongi brings the car in front of the king. This is nothing new.

12)what I think is that this happened many times, the king had seen him many times, the people he beheads are other Yoongis, you can even see the black hair peeking out of the boxes when he holds them.

13) I think that every other time he won and that is why he`s so confident and not afraid at all, and that is why people in the village are not unhappy. In the kingdom where king beheads that many people, people don`t walk around in the market that happy.

14)I think the butchers are Yoongi`s allies and this time he`s not running away from the king but lets the butcher take him into the palace and make it appear like he`s another one. And I think this all is a very elaborate plan.

15). Also, I think that butchers are time-traveling too because that gun is from the 19th century. That car is from 2006. I think they all try to help current yoongi kill the old evil one.

16)in the end I think that it`s a very elaborate metaphor: black-haired Yoongi is today`s Yoongi, best version of himself, not alone. And he`s ready to beat the final boss, his oldest (first) evil reincarnation. Maybe others couldn`t do it but he`s ready. And he does it.

17) I think that the most important thing here is both of them being smart and powerful but one is evil and one learned to have crew and allies and be a better version of himself and also learn from mistakes.

18) I want to say that this is only a theory and only from what I know and could look up. I`m not saying that I`m right, I`m just sharing my thoughts about a possible plot. ^_^

thank you for listening to my ted talk ^_^

+ I think I missed a looot of things because I'm by no means expert in Korean culture. I try to learn but it's a process so if I was waaay off in some parts, I'm sorry ^^