| “ | OH, IT'S JUST A SIMPLE NUMBERS GAME. WHEN YOUR HP DROPS TO 0, YOU LOSE! | „ |
| ~ Jevil before the battle. |
| “ | I CAN DO ANYTHING! | „ |
| ~ One of Jevil's memorable lines. |
Jevil is a supporting antagonist in metafictional role-playing video game Deltarune.
He was once the court jester of the Card Kingdom who is a friend of the court magician Seam. At one day, he met a "strange someone" and then his personality has shifted permanently. According to Seam, Jevil had been talking about bizarre things that either makes sense or not after encountering an enigmatic figure (Either Someone from Beyond the Fourth Wall or The Knight). Because of him viewing the world is just a game and everyone else are his participants, Seam, under the order of four kings, forced to lock his comrade in the dungeon cell. He is the chapter 1's optional superboss and one of the holders of Shadow Crystal.
He's voiced by Toby Fox (In Japanese dub, who also voiced Tasque Manager in the same game), the creator of the game, and designed by kanotynes. 
What Makes Him an Ensemble Dark Horse?[]
- From Chapter 1, everything about Jevil is the most positively discussed topic within the Deltarune Fanbase for the vague hints of Deltarune future Superbosses and some foreshadowing hints about the future chapters, such as being one of the holders of Shadow crystal and being Satanic Stand-Ins with implied have met "The Knight".
- Jevil himself is a goldmine of memes, especially when it comes to his iconic voicelines.
- Jevil's character is praised by the players for a surprisingly nihilistic self-aware character that has the aspect of Sans in Undertale. While both Jevil & Sans are self-aware about the metafictional world, they have different outlooks. Sans was driven by apathy by inability to change anything if the player did the no-mercy run. Jevil, on the other hand, was motivated for seeking elation and views the world as his personal playground and jumps an opportunity to have a good fight. While Sans is a route boss that can only be fought in the No-Mercy Run, Jevil is an optional boss in Chapter 1.
- Most of the Jevil's attacks involve bullet hell, Merry Go Round, transform into Devilsknife, and then covers the entire screen. Most of them tests the player reflexes to try keeping the party's HP from dropped down to zero. 
- Jevil can be defeated in two ways, by either with violence or participating his game. The player will be rewarded with an equipment depending on the way how you beat him. 
- If defeated with violence, Jevil's body is unbreakable despite his HP is reduced to 0, but he nevertheless satisfied playing with his three "participants" and then transforms into an equippable DEVILSKNIFE.
- If defeated with participate his game until he's exhausted (Requires Ralsei to do the Pacify spell), Jevil is exhausted after playing along with The Lightners. Jevil will reward you JEVILSTAIL instead. 
- Jevil's Boss fight is the most fondly remembered by the Deltarune players for the surprise difficulty and actually has a voice clips, setting the trend of Deltarune Super Bosses. It also accompanied with beautiful visual effects of a spinning carousel.
- While Seam, under the King's order has to lock his comrade Jevil while becoming insane, King also has stated that he genuinely express regret for imprisoning him to prevent him wreacking havoc because he was an amusing fellow before meeting The Knight.
- Jevil's pre-battle theme has a creepy circus melody and has catchy tone in his boss theme, "The World Revolving".
- Aside the "Don't Forget" leitmotif, there's also a musical spoiler that both of his themes involve W. D. Gaster's theme leitmotif. In which implies the encounter between Jevil and Gaster before the former becomes a self-aware lunatic.
- Additionally, "The World Revolving" Leitmotifs are also used in Spamton's themes, "Dialtone" and "BIG SHOT". In which, also implies their connection as the rivals.
- When chapter 3 & 4 has been released, fanbase laments that Jevil could have been interacted more with the fellow Shadow Crystal Holders such as Spamton, Gerson, and the Knight as he was underutilized, aside from being a comical arch-nemesis of Tasque Manager.
Trivia[]
- His name is a portmanteau of Joker / Jester and Devil.
- The carousel from his battle arena is a picture of Galloper Carousel from The Hoppings, an annual travelling funfair in Newcastle, England.
- And the "3D" Carousel background is actually a 2D optical illusion.
- Jevil, C. Round, Clover, Seam, and Rouxls Kaard are the Deltarune Ensemble Dark Horses who originates in the first chapter.
- Jevil, and Gerson (Deltarune) are the Deltarune Superbosses who became Ensemble Dark Horses.