Darkner
Our purpose - Darkners' purpose - is to assist them.
It's the only way we can feel truly fulfilled.
Darkners (JP: ダークナー) are a class of beings in Deltarune. They live in the Dark Worlds, as opposed to the Lightners that inhabit the Light World and plants, who exist in different states in both worlds. They are the keepers of the Dark Fountains, which give them a physical form and sentience. While they exist to aid Lightners, Darkners can develop their own personality and interests. In each Chapter, most Darkners can be recruited to Castle Town, where they can remain sentient.

A Darkner's form, personality, and bullets are influenced by their Light World form, which can range from small objects, such as playing cards and figurines, to large TVs. They can also be conceptually based, such as computer viruses or spam emails. Rarely, a Darkner can be formed from the memory of a Lightner, which reproduces said Lightner's likeness in select Dark Worlds.[1]
Multiple of the same object can have Darkners sharing the same appearance, such as Plugboys, but can have distinct traits and memories, such as Ramb. These can be influenced by a Lightner's relationship with the Darkner's Light World form, as Kris had favored playing with Ramb when they were a child.[2] An object also does not always become a Darkner; for example, a QuillPen can either become a Winglade Darkner or turn into an equippable sword in the Dark Sanctuaries.
Darkners's dialogue portraits are depicted in full color, in contrast to Lightners having black and white Undertale-style dialogue portraits.

A Darkner's role can vary depending on their appearance and the Dark World. They can live a normal life akin to Lightners, offer support,[3] or partake in encounters. Darkners are capable of casting magic, which can appear as bullets.[4]
While Dark Worlds can be newly-made, Darkners have a history far before their Dark World is formed. They can have relationships with other Darkners outside of the current Dark World and can also recall events and locations before and when its Dark Fountain forms,[5][6][7] or their Light World form's interactions with Lightners.[8][9]
At the end of a Chapter, all Darkners repay the party's kindness in some way if they are all SPAREd. They can also assist the party by joining Kris's inventory as Key Items, or can transform into equipment. In the latter state, they are less active, but can transform back or comment in certain situations.[10]
Darkners can also aid the player. Some are aware of the player's chosen name in the introduction sequence,[11] and can offer advice on game controls,[12] gameplay,[13] or SAVING.[14]
When a Dark Fountain is created, not all Darkners that gain sentience can "belong",[15] and they eventually turn to gray, cracked statues.[16][17] When this occurs, the Darkner's colors slowly fade, they weaken, and are less energetic. This slow petrification is described as feeling "cold".[18] Darkners turning into stone statues can be prevented or reverted if they live near the Grand Fountain, as it is made of "pure darkness".[19]

Once a Dark Fountain is sealed, Darkners revert to their Light World form and lose sentience. Their condition afterwards can vary based on the actions taken by Lightners and other Darkners. In this state, Darkners can be physically transferred to other Dark Worlds if a Lightner transports their Light World form. Some Darkners are exceptions, as Ralsei and Starwalker can transfer on their own.
According to the prophecy, Darkners and Lightners once lived in harmony. The Earth would be doomed to a cataclysm known as the Roaring if the balance of Light and Dark is disrupted by excess Dark Fountains. Ralsei states if this were to occur, Darkners would become "crushed by the darkness" and turn to stone.

Card Kingdom's denizens once lived in harmony with the Lightners, but when the classroom that makes up their Dark World went unused, they believed the Lightners abandoned them. When a strange Knight appeared, King became vengeful and usurped the throne, intending to cast the world into eternal darkness. Many of his former staff, fired during his rage, were imprisoned or forced to find work elsewhere outside of Card Castle.
In Chapter 1, many Darkners follow King and Lancer's orders. While most reluctantly comply, they can be easily persuaded via ACTing during encounters. King primarily enforces Lancer to command the minions. However, this approach backfires on him when Lancer befriends Susie, and through her, the party. This allows the party to reconcile their internal friction and confront King.
If Card Kingdom's Darkners were defeated non-violently, they eventually arrive to dethrone King in favor of Lancer.[20]

In Chapter 2, the Cyber World Darkners are largely on good terms with Lightners. Many of them live peacefully, though Queen uses control wires on Plugboys and select minions for her own ends.[21] This is due to Queen misinterpreting the Knight's actions and believing the Cyber World's expansion would benefit both Light and Dark Worlds. In response to her extreme actions, Sweet Cap'n Cakes formed a resistance.
At the end of the Chapter, Darkners can improve the Thrash Machine's HP. After the battle, Queen is easily persuaded against making multiple Dark Fountains after Ralsei informs of the Roaring.

In Chapter 3, many of TV World's Darkners are Tenna's employees. Despite this, most of them dislike working for him, and Shuttah states that disinterested Darkners left TV World through unknown means.[7]
The employees and Tenna are friendly during and after TV Time, and many are familiar with Kris due to being objects in the Dreemurr residence. However, Tenna keeps the Lightners preoccupied from sealing the Fountain out of fear of being discarded. His desperation leads to him pressuring his employees to recapture the party after they escape his show, causing the employees to quit.
Several of the inhabitants also originate from other Dark Worlds, such as the Pippins and Ramb. Some of these Darkners begin to turn to stone by the Chapter's end, though the Pippins, and a Rabbick who was brought stuck to Kris's clothes, appear to be compatible with the world despite originating from Card Kingdom.
If Pippins and Shadowguys have been recruited, they help Susie find and repair Tenna's remains before the Fountain is sealed.

In Chapter 4, the demeanor of Darkners can vary in the Dark Sanctuaries. In general, these Darkners are on good terms with Lightners, and are aligned with the party due to the world's dedication to the prophecy. However, some of the Darkners attack as they mistake Kris for the Knight due to their armored attire.[22]
In the Dark Sanctuaries, Darkners do not appear to have a single leader, though they respect the Darkner reproduction of Gerson, as they listen to his instructions and are instantly spared by him.
For unknown reasons, the Dark Sanctuaries has several statues of Darkners that are incompatible with its respective Fountains, and are often referred to as fossils by the active Darkners. In the 2nd Sanctuary, the Darkners that were former statues are instead sentient, and vice versa. Many of them are variants of Organikks, who ask cryptic questions and occasionally allude to gameplay or the prophecy. In the 3rd Sanctuary, all Darkners are sentient and no longer petrified.
If at least one Darkner in the Dark Sanctuaries is recruited, they realize their mistake and work together to save Jackenstein and the party from a long fall while pursuing the Knight.[23]
Chapter 5, taking place within Flower King, has a heavy emphasis on plant- and garden-themed Darkners. In addition to this, it is revealed that actual plants given form and awareness by a Dark World are a distinct phenomenon from actual Darkners, since they were already living things in the Light World.
- ↑
Darkners patterned after the memory of a loved one...
— Ralsei, Chapter 4
Tend to only appear in very specific darknesses.
... even if we tried to bring him to Castle Town, he... - ↑
He was a plug, but because you played with him like any other toy, it made him feel special.
— Pippins, upon checking the petrified Ramb, Chapter 3
Might have given him a little bit of an ego, in fact... - ↑
Hey, kid. We managed to fix up this old thingamajig for you.
— Jigsaw Joe on the shortcut door, Chapter 1
It's some kinda door... It can take you anywhere you want in the world! - ↑
Oh, healing magic? It's simple, Susie. Anyone can do it.
— Ralsei, Chapter 2 - ↑
— Sweet Cap'n Cakes, "About Queen", Chapter 2
Queen wasn't always so... harsh.
No, she WAS! She just got WORSE somehow!
It wasn't 'til that DARK FOUNTAIN showed up,
That she started going into overdrive.
"Knight" this, "Knight" that, "Fountain" that...
Like, what does that Knight even have going for it that I don't!? C'mon!! - ↑
The day he was to be evicted from the Queen's mansion,
— Another Cyan Addison in the Trash Zone, Chapter 2
I went to his room to check on him... - 1 2
There once was the great wilderness here! Yes...
— Shuttah, Chapter 3
But, the world became the theater, and us, children of Tenna's contract.
Those that did not sign the paper, set off for the far land and were forgotten. - ↑
That robot was the embodiment of a Lightner's dream.
— Swatch, "Basement Robot", Chapter 2
A dream I helped create... once.
Splashing color from the motion of their hand. - ↑
Oi, Kris, luv! It's me, Ramb! You and your brother took me here from the Library!
— Ramb, Chapter 3 - ↑
TENNA - THE [Tragic businesmen] THAT [Died] AT THE [Now] OF THE [Story]
— Check versus Tenna with Dealmaker equipped, Chapter 3 - ↑
Oho. Welcome to <NAME>Town!
— Rudinn, Chapter 2 - ↑
Right before Susie's RUDE BUSTER hits the enemy...
— Pippins in Star Changing Room post-Round 2, Chapter 3
Press [(CONFIRM)] to deal extra damage!
You'll know you did it right, 'cause the sound will change a little bit. - ↑
You and Virovirokun explained how battles work to Noelle.
— Narration, Chapter 2 - ↑
(SAVE and take a break anytime you want, OK?)
— Ralsei, Chapter 2 - ↑
You see, each Dark Fountain creates a different "world."
— Ralsei, Chapter 2
A "world" whose Darkners reflect the will of its fountain.
But, though those Darkners can exist in their own worlds...
They might not "belong" if they go to another one. - ↑
A stone statue. Strangely, it looks like Lancer...
— Lancer (item description), Weird Route, Chapter 2 - ↑
Y'know, I'm a bit worried... ain't Pippinses originally from Card Castle?
— Zapper, Chapter 3
If dis guy turned ta stone, I ain't sure what I'd do... - ↑
I... I'm fine! Just... very...
— Lancer, Chapter 2
Cold... - ↑
Castle Town's Grand Fountain is made of pure darkness.
— Ralsei, Chapter 2
As long as it stays flowing, any Darkner can live there. - ↑
Sorry, Dad! You're being overthrown!
— Lancer, Chapter 1
When I told everyone you were fighting the Lightners...
Everyone remembered how kind they were!
They decided they'd rather have a king...
That accepts them!
Me!!!
Now I'm the dad!!! - ↑
WEREWIRE - Controlled by the Queen's wire, it's sleepwalking through a nightmare!
— Check versus Werewire, Chapter 2 - ↑
The others here believe you will bring trouble to this place.
— Wafer, Chapter 4
They say, "the knight with the blade casts a great shadow on the land..."
I have no proof that's you. But don't be harsh to those that fight you. - ↑
We apologize for our belated realization...
— Darkners, Chapter 4
But you three are the heroes, are you not!?
The story of your kindness... Has become legendary!!
And so, posthaste, we come to aid you in your battle...
Go forth... and defeat the Knight!