Anjin

"I'm a glitch in his little universe... a universe you don't belong in anymore."

- Anjin (As Lachie)

Anjin, despite being presumed to be involved in the overlaying story, there was never anything much to prove this until The Good, and the Plain where he was confronted by Detective Lachie after the first outro. Anjin was previously known as The Darkness, however after How to Complete a Trilogy, he is now known as Anjin. It is to be presumed Lachie (Character) does not know his name is Anjin however, as he has never called him this and the only way we as viewers know his name is because Detective Lachie found his channel.

Halloween in Salem Town
Anjin's first appearance was a main character of this episode. Anjin at the time went by the 'Darkness' persona, and was the only name we had for him until How to Complete a Trilogy. In this episode he served as 'the negative parts' of Lachie (Character)'s review, actually appearing as a sprite for the majority of the episode. He is quite negative, with Lachie usually rebutting his negative remarks with something positive or something to negate his comment. Finally, at the end of the episode, Anjin clenches his fist to become that of Lachie's, the first real indication of some form of shape-shifting. We are yet to learn the limits of his abilities.

Ranking the Super Mario Galaxy Galaxies
Anjin doesn't directly seem to appear in this episode, however, a voice that sounds exactly like Lachie's recommends to review Super Mario Galaxy, which seems to correlate with his later tendencies to force Lachie to play games through his sleep. At the end of the episode, Lachie also asks who is filming the video, indicating that the voice in the beginning isn't just a joke and is related to the plot. So, while the voice doesn't align with other versions of Anjin, this could be him in a developing stage to his current antagonistic state.

My Favourite 2D Platformers
In this video, Lachie is forced to create a video with Donkey Kong Tropical Freeze against his own will. Lachie goes to sleep after playing Shovel Knight, hoping to create a video on it the following day, yet he is instead spoken to through the form of a vortex-like vision and a distorted deep voice. He then wakes up to Donkey Kong Tropical Freeze on his TV instead, forcing a review we never actually saw. This voice was extremely similar to that of Anjin's 'Darkness' persona, and is confirmed to Anjin later on as he continues to speak to Lachie, yet Lachie is currently unaware of the identity of this voice. While there is not a proper end scene in this video, there seems to be some inaudible noise with the same tone as Anjin's voice in the outro.

NOT the Worst of the Trilogy!
Surprisingly, Anjin has no appearance in The Entire Story of the First Game and barely any appearance in this episode either. At the end, the policeman points his finger towards a screen with the vortex sequence in My Favourite 2D Platformers, and gets frustrated with what this inaudible noise in the sequence is. He has it decoded, and it seems to shout “I'm the one in control!” only to have a deeper voice play back to the viewer with the same phrase, supposedly confirming it was actually Anjin talking, the filter just decoded wrong. This mistake wouldn't be too hard to make as Anjin's voice is seemingly just a corrupted version of all the other Lachie's of this universe. At the beginning of the episode, Lachie also mentions that he doesn't know who paid the bail for his release after last episode, and chances are it could have been Anjin's doing.

The Good, and the Plain
Anjin is a major focus of this episode, with Detective Lachie actively searching for him and trying to find out what is going on behind the Lachieninja channel. Anjin appears in the form of a vortex again in this episode, communitcating cryptic messages, which lead to a visual secret being found out involving the Anjin channel that has since been revealed to exist in How to Complete a Trilogy. At the end of the episode, Detective Lachie manages to meet with Anjin, who starts by first posing as a clueless Lachie, but after Detective lets out that he knows too much, Anjin switches to his regular persona, annoyed with Detective managing to once again come back to him after How to Complete a Trilogy, and banishes him to a different world, not filled with Lachies. How he has the power to do such a thing is a mystery.

How to Complete a Trilogy
Anjin is once again a large focus of this episode, however less time is spent trying to find him. The only time he appears is in the pre-outro scene. Suprisingly, Anjin is quicker to do away with Detective Lachie in this instance then the second time he comes to see him. Anjin does not attempt to act as a clueless Lachie, he instead simply knocks Detective out by punching him. He then says:

"Lachieninja will rise again! And it will be all me!"

- Anjin

In the post-outro, Anjin pressures Lachie (Character) into uploading the Trials and Tribulations video via vortex, however, he also calls it busted and has audible frustration when he complains as to how Detective Lachie's clips were making it in. These allude to the idea that the reason The Good, and the Plain was released before this episode, despite this one being a prequel, was because it was broken somehow and Lachie stumbles onto it. In this scene is also where Detective Lachie finds the Anjin Channel. This channel was created on May 10, 2019.

Halloween (Close Enough) in Luigi's Mansion
In this episode, Anjin returns to his roots, and like in Halloween in Salem Town, he acts as the negative parts of Lachie's review. Before the episode really kicks off though, we are introduced to the digital realm void, a place where Lachie (Character) is being kept in chains. Anjin tells Lachie that his channel is doing well and if he keeps complying with him, he may be able to live freely again.

After the review is complete, Anjin tells Lachie that he was horrible and regrets giving him another chance, presumably meaning talking freely of his own opinions. He insults Lachie and talks about how it's his fault for starting this and that he 'wouldn't have to be here,' and once again mentions that Lachieninja is coming back by his own hands.

Devoid of Christmas Spirit
Anjin lacks much appearance in this episode, being overshadowed by the Spirits of Christmas. However, despite this, the Spirit of Christmas Present appears in a form similar to Anjin, representing how Lachie's present is so overcome by Anjin. This spirit is able to show Lachie visions of the real Anjin in the digital realm void, where he is seen taking some sort of essence, most likely whatever deeply remains of his past memories and experiences to be taken into the physical world where it appears he was later shot.

Something of note is that it is commonplace to assume that Anjin is actually the reviewer for this episode, not Lachie. He abandoned Lachie after the results of Halloween (Close Enough) in Luigi's Mansion, but more substantially, Lachie in this review mentions his past experience with the game when he was younger. Lachie has been self-aware in review segments of the fact that he remembers nothing in the past by making half-witted jokes about it before, proving that this is not him.

Who is Anjin
We know nothing about how this character came to exist. He bears a complete difference from every other Lachie in Lachie's world, even calling himself a glitch.

Why Control Lachie
Nothing about the purpose of Anjin is known. It is unknown why he is going after Lachie or basically anything about his motivation. This is one of the biggest mysteries in the story. He has gone on record saying that he "will bring Lachieninja back," however, why he wants this or why doing what he is doing would help that is quite unknown.

Lachieninja
Something that is known for sure is that Anjin is somehow related to the Lachieninja phenomenon, as he has said he wants to bring back Lachieninja.

Trivia

 * Lachie (Creator) seems to have a minor distaste towards people calling Anjin The Darkness after his real name was revealed. Only filthy casuals call him that. The Darkness is the reviewing persona he takes on.
 * Anjin being a dark counterpart, while quite generic in premise, is probably inspired by the abundance of this trope in media Lachie enjoys, as it is very Nintendo-esque, with countless examples.
 * It appears Anjin was planned to be of some substantial importance from the very beginning, despite Lachie (Creator) being unsure as to go through with it for a while, as the post credits scene of Halloween in Salem Town suggests the beginning of a story, with a cliffhanger scene.