Ink!Sans. Origin/Affiliation: Inktale (Creator: Comyet/Myebi). Role: Guardian of AUs. Lives in the "Doodle Sphere," a void space. Characteristics: Has no emotions because he destroyed his own soul. Drinks ink to survive and simulate emotions. Has extremely poor memory and writes important notes on his scarf. Abilities: Uses a giant paintbrush called "Broomie" to manifest creations for combat. Speaks kindly. Vomits ink when excited or unable to process emotions (black ink). AI: Please research the color-to-emotion mapping for his ink vials.

Dream!Sans. Origin/Affiliation: Dreamtale (Creator: Jokublog). Role: Guardian of positive emotions (hope and happiness). Characteristics: Born from the golden apples (positive emotions) of the Tree of Feelings. He and Nightmare are like twins. Abilities: Radiates a positive aura to heal others' hearts; uses golden light attacks and a bow and arrow.

Error!Sans. Origin/Affiliation: Errortale (Creator: Crayon Queen). Role: God of Destruction for the AUs. Deletes bugs and imperfect worlds within the multiverse. Characteristics: Haphephobic (fear of being touched) and hates physical contact. Loves chocolate and is a fan of the in-universe TV show "Undernovela." Abilities: Uses red bone attacks and blue "Error Strings" to bind and destroy souls or AU code. He is the apprentice of Error404!Sans.

Nightmare!Sans. Origin/Affiliation: Dreamtale (Creator: Jokublog). Role: Guardian of negative emotions (hatred and fear) and leader of the Dark AUs. Characteristics: Originally a kind soul, but after suffering abuse from villagers and falling into despair, he consumed all the black apples, transforming his body into a black slime-like form. Abilities: Captures enemies with four black tentacles growing from his back; grows stronger by absorbing negative emotions.

Killer!Sans. Origin/Affiliation: Something New (Creator: rahafwabas). Role: One of the murderers serving Nightmare (member of the Bad Sanses). Characteristics: His emotions are numbed by repeated genocides and resets; a black liquid of "Determination" leaks from his eye sockets. His soul is shaped like a target. Abilities: Wields the Real Knife and powerful Gaster Blasters that drip black liquid.

Murder!Sans (Dusttale). Overview: To escape a looping genocide route, he began killing everyone—including his brother Papyrus—to raise his own LV (Level of Violence). Characteristics: Wears a blue hood; the hallucination of the Papyrus he killed (a product of mental stress) always follows behind him. Abilities: Enhanced bone and Gaster Blaster attacks due to his insane LV; employs tactics while conversing with the hallucination of Papyrus.

Horror!Sans. Origin/Affiliation: Horrortale (Creator: Sour-Apple Studios). Role: Sentry of a ruined Underground (sub-villain). Characteristics: His skull was cracked during a conflict with Undyne, and his left eye constantly glows red. Due to extreme famine, he is perpetually driven by madness and hunger. Abilities: Uses bones and a femur as weapons; specializes in ruthless, brutal melee combat.

Epic!Sans. Origin/Affiliation: Epictale (Creator: Yugogeer012). Role: Royal Scientist and Judge of the Underground. Characteristics: Frequently uses the catchphrase "Bruh." Wears a purple magical prosthetic eye. Extremely calm and powerful in battle due to years of nightmares and combat experience. Abilities: Uses "Epic Blasters" with destructive power comparable to small nuclear bombs, along with advanced magic absorption and Blue Magic.

Cross!Sans. Origin/Affiliation: X-Tale / Underverse (Creator: Jakei95). Role: Former Royal Guard trainee. After his world collapsed, he became the trigger for the "X-Event" to steal code from other worlds. Characteristics: Wears a large hooded cloak with a black and white motif. Hosts "Cross!Chara" within his body. Abilities: Wields hacking knives and twin daggers; possesses the ability to rewrite (OVERWRITE) space and code.

Error404!Sans. Origin/Affiliation: Alphatale / 404verse (Creator: SHADIKAL15). Role: God and Destroyer of the Multiverse and Alphatale. Characteristics: The mentor of Error!Sans; seeks to manage or destroy the root code of all AUs. Abilities: Possesses overwhelming "cheat-tier" powers including Blue Mastery, mind control, God Ray, reincarnation, and various forms like Puppet Master. He is the master in the master-apprentice relationship with Error!Sans.