Ralsei is a walking mystery. He looks exactly like Asriel (Kris's absent brother), but wears black robes. He is excessively kind, teaches the player to pacify enemies, and knows the prophecy intimately. Suspiciously, Ralsei is the only Darkner who does not turn to stone when entering a different Dark World (Lancer does). He also seems to break the fourth wall, understanding "Save" files. Fan theories suggest Ralsei is either a manifestation of Kris's grief or the true secret final boss. The "Weird Route": Deltarune’s True Villainy Undertale had the Genocide Route. Deltarune has the Weird Route (aka the SnowGrave route). It is not simply "kill everyone"; it is psychological torture.
The game opens with a prophecy. A legend of three heroes—a Human, a Monster, and a Prince from the Dark—who will banish the "Roaring Knight" and balance the "Fountains." Deltarune
Susie starts as a standard bully archetype—loud, aggressive, solves problems with an axe. But Toby Fox subverts this instantly. In the first Dark World encounter, Susie refuses to "Act" (the mercy system). She fights. You can't stop her. However, as the game progresses (specifically her solo adventure with Lancer), Susie discovers friendship. By Chapter 2, she is arguably the moral compass of the group, protecting Ralsei and trying to understand the Light World. She is proof that Deltarune is about the illusion of choice; you cannot change Susie’s heart—she changes it herself. Ralsei is a walking mystery
Kris is the silent protagonist trope weaponized as horror. Unlike Frisk (who was a blank slate), Kris has a history. They are a prankster who plays piano, hates hugs from their mom, and is allegedly the "weird kid" in town. The fact that you control them implies a parasitic relationship. When Kris rips the soul out, they walk stiffly, drag a knife, and smile creepily at the camera. The question remains: Is Kris saving themselves from us, or are they plotting something worse? Suspiciously, Ralsei is the only Darkner who does
It is a game where the "Mercy" button exists, but it feels desperate. It is a game where you want to be friends with everyone, but you can feel the strings of the puppeteer (Toby Fox) pulling your arms. It is hilarious, with jokes about internet trolls and anime conventions; but it is also horrifying, with themes of loneliness, loss of agency, and consent.