The Ends, Drifters and collateral all represent pieces on a chess board
I don't have a lot of evidence for this, but i'll do my best.
Abe no Seimei and the Black King are, of course, the Kings. It's an important piece, but is restricted in it's movement. Abe no Seimei doesn't seem to take an active hand in leading the Drifters but does bring them together and unite them under one cause, and the Black King is the life of his army.
Hijikata and Toyohisa represent the Queens, the most powerful and dangerous piece in a game that are useful for harassing the enemy and obtaining an early checkmate. Interestingly, there's such thing as a Queen sacrifice; to sacrifice the Queen and gain a more favorable position. Both Hijikata and Toyohisa seem to want to die in battle for the betterment of their cause.
Nobunaga and Mitsuhide are the Rooks, who in the opening of the game tend to not move at all or only very little — often hanging back, but in the ending are considered to be incredibly valuable with it's ability to move unobstructed by pawns and control a large area of squares. They are also considered ideal for checking the King. That said, there is such thing as an exchange, where a rook is taken by losing a minor piece such as a bishop or knight. Losing an exchange is considered detrimental to a player, due to the value of the rook.
That's all I got so far, but it's interesting to think about considering the whole black and white color scheming of Easy and Murasaki.
EASY and Murasaki are having a lover's spat.
Easy is first introduced interacting with Murasaki, as if she wanted to have a civil conversation, but was too tsundere to get it right. The whole deal with Drifters and Ends is just EASY taking out her frustration on Murasaki, getting him to admit that she is right about something they had a disagreement with. The animosity between Easy and Murasaki isn't like two deities trying to kill each other, but rather, two deities trying to impress some sort of philosophical belief upon the other. The world under their supervision, just happens to be the poor chessboard the pair are battling on.
- Considering that EASY reaches to people who were "rejected" (or abandoned) by humanity, which in a sense seems to be what Murasaki advocates to - smiling when Toyo says they won't be pawns and showing displeasure when he talks about fate - it does sound like a lover's quarrel of a cosmic scale; but at the same time, it does seem like she is the one who is far more emotionally invested in this, whereas Murasaki acts dismissive of her; so it could be that he was the one rejecting or abandoning her (take whatever meaning you want with it).
The Black King is Dr. Martin Luther King Jr.
Dr. King preached equality for all people and for his efforts he died a violent death, killed by an assassins bullet. He was collected by EASY and turned into the Black King. Ends seem to get powers that are somehow related to how they lived in their previous life. For Dr. King, who was a reverend and follower of Christianity/Jesus, he gained the powers of Christ. He saw that trying to save humanity is what lead to his death so he decided to change tactics by saving another group that is similarly persecuted in this new world he lives in. The Black King is currently trying to enlighten and give advancement to the "inferior" races, much like Dr. King did for Civil Rights. This would be a better plot swerve than the Black King simply being Jesus.
- In a story where the "heroes" are bloody warriors tyrants and Adolf Hitler was actually enlisted amongst their faction, that would be a major thematic counterpoint. It would also be extremely offensive to portray a man who dedicated his life towards a peaceful harmony between the races as the power behind a genocidal campaign. I could see Jesus Christ turning on his own principles because much of what we know about is distantly obscured by myth. However MLK's life is still fresh in the public memory and preserved through biography.
- Joan of Arc was among the villains and they're using historical characters. It's not a stretch to say MLK isn't out of left field.
- Hirano is known by the meme of "Nazi's eating babies". Let's not put anything past him.
The Black King is Saint Peter, the Apostle of Christ
Simon Peter fits a lot of the physical information we have of the Black King. While Jesus would still have looked phsyically fit and healthy since he was only crucified at age 33, Saint Peter was around his 70's when he was Crucified as Christ, though he requested for it to be upside down so that he could show his humility to his Savior. It also accounts for his Miracles, since in Matthew 10:8 Jesus told them to go and perform miracles (healing the sick, curing lepers). Another point I have in the WMG is that Saint Peter was also a proponent of the Gentiles being allowed into the Christian faith. Acts 19:46-47 talks about how the Jewish people rejected the teachings, and thus they have turned to witnessing to the Gentiles.
This fits what we see happening in Drifters universe. Either the death of himself traumatized Peter much like it had to Joan of Arc, or he saw what the Humanity of this world was doing to the lesser creatures. So instead he wished to be a savior to these lesser groups, it is why he clearly states that he is not a god, still humbling himself before Jesus Christ, but also refers to himself as "the Inexorable Tribulation" knowing that by imitating Jesus, he is acting like an anti-christ.
The Black King is Grand Master Meio, from Strider
In the original Strider games, Meio is credited with being able to create life out of will. The Black Lord says about how creatures like Orcs, Goblins, et cetera, will replace humans in the world of Drifters, akin to Meio's desire of wiping out human race to repopulate Earth with his own created race. The Black Lord's speech, while not similar to Meio's iconic "All sons of old gods, die", sounds really similar.
The Whole Series is But One Battle in a Proxy War
Speaking as someone who has only watched the first three episodes, I'm vaguely reminded of the book series Animorphs, where the whole series turns out to be a single battle in a proxy war between two god like entities who can't duke it out without destroying everything. EASY immediately struck me as a
Greater Scope Villian, the kind who empowers the villains, but the protagonists never actually fight or defeat (though they will thwart their plans) and I noticed how there were so many gates in that hallway Murisaki is in, presumably each one leads to a different world. The two are dueling across all those worlds, constantly. We only see one small faction, one small group of the champions of both sides, and that's all we're going to see.
The Ends and Drifters were
empowered by Easy and Murasaki respectively.
Naturally, if you're going to use historical figures as your pawns in a cosmic contest, it'd help to give them a fighting edge they wouldn't have otherwise. How the Ends and Drifters are empowered also reflects the beliefs of their benefactors. Easy, who believes in great shows of force and crushing her opposition, gave her Ends very overt supernatural powers to overwhelm all obstacles. Murasaki, who values strategy and tactics, was more subtle with his gifts to the Drifters, making them
Empowered Badass Normals. We've seen a few examples of his gifts to the main cast.
Toyohisa always charges into the fray headfirst, heedless of his own wellbeing. Murasaki raised his natural durability so that he would be Made of Iron. Yoichi was always a skilled archer, so Murasaki simply elevated him to Improbable Aiming Skills. Watch Yoichi's demonstration of endlessly Splitting the Arrow during archery training. For Nobunaga, Murasaki improved his own capacity for destruction. His home made gunpowder, which decimated an Orte stronghold, vastly exceeded Nobunaga's expectations of the crude substance by his own admittance. Perhaps Murasaki is pushing the odds in his favor when it comes time to blow things up or burn it to the ground.
Unless someone else has done so, this show is the kind of thing that’s in their wheelhouse.
The Black King isn't Jesus, but Hong Xiuquan
It would certainly make him more fitting for the role of
Big Bad than Christ Himself while still "being" Jesus. For those unaware, Hong Xiuquan was the leader of the Taiping Rebellion and claimed to be the brother of Jesus Christ.
The Black King is Shiro Tokisada Amakusa
He was a Japanese Christian rebel who tried to protect his people from mistreatment and genocide, was attributed with mystical power (including healing and walking on water) who died horribly (via crucifixion, according to some I’ve talked to, but I’ve never seen confirmation from an actual expert or even the internet so who knows) who is often displayed as a
Fallen Hero in Japanese media. He would fit perfectly, assuming the
Saint Young Men reference is just an omake thing.
