This is, in essence, a sped-up version of one of Clover’s attacks. When talking to him for the first time, Jevil explains that while it appears he is locked in a cell, he is the only person who is actually free while everyone else is locked away. However, he goes on to explain that he is lonely and that he wishes for more people to be “free” with him. He instructs the party to find the key to open his door, noting that the “OLD SHOPKEEPER,” Seam, knows something about it. Later in the battle Jevil will begin throwing multiple of the aforementioned attacks at once.
Jevil, unlike Spamton, does not say anything about it. After retrieving the three, Kris takes them to Malius, who combines the parts into a single Door Key. The smith then warns the party of the evil energy the Key holds and advises them not to use it. After Kris uses the Key to Jevil’s beer and bodybuilding cell, a smaller door materializes and opens. Jevil waits at the far right of the area, and wants to “PLAY” a “SIMPLE NUMBERS GAME. WHEN YOUR HP DROPS TO 0, YOU LOSE!” Jevil then engages the party in combat. He is Chapter 1’s bonus boss, and thus a holder of a Shadow Crystal.
It is possible to lose to the second boss Papyrus, but he won’t kill you, just trap you in an easily escapable cage. The only bosses that actively try to kill you directly are Undine, Flowey/Asriel, and Asgore, and the later does so incredibly regrettably. Muffet is just a fan character inserted into the game so she doesn’t count, which also means that other backer character like So Sorry are also not included. There are two different ways to defeat Jevil like with the majority of Deltarune battles.
This guide will show players how to find and defeat this ultimate Deltarune challenge. Jevil can be tough for some, especially those not used to bullet hell games. Eventually I prevailed and now has a save for fighting Jevil just for fun.
I’d also disagree in saying that Jevil was casual during his fight. He can still kill the party, and he’s defeated by tiring him out, not just by him giving up. I think it’s weird some people are calling you out for not doing something that really isn’t obvious. At least it’s not like Reddit where people yell at you for “complete missing the point of the game” or tell you you’re a bad person in real life for playing the game the way you want. And there have been a few games where some eniemies I faced had their own grey areas in fights such as Ganondorf from TWW.