Bonus Boss Enemies

Optional boss enemies in Deltarune, and generally the most difficult foes in their respective chapters. So far, each chapter has featured one bonus boss, each carrying a Shadow Crystal, with chapters 3 and 4 carrying a second more minor bonus boss.Certain bosses can be defeated by FIGHTing or ACTing, with a different item earned as a result. Others may only have one way to beat them, and thus one item that they offer.

Main Bonus Bosses[]

• Jevil: Formerly the court jester of Card Castle, he went mad after meeting a "strange someone" that led him to see the world as no more than a game, and had to be sealed away by Seam on the ?????? floor in Card Castle. Despite imprisonment, he claims to be truly free, and that the outside world is what's imprisoned. Acts as the bonus boss of Chapter 1.
  • Defeated by ACTing (tiring him): Jevilstail (Armor)
  • Defeated by FIGHTing him: Devilsknife (Weapon)
• Spamton NEO: Originally Spamton, a salesman who wanted to be a "[[BIG SHOT]]," but fell on hard times when the stranger who helped him succeed disappeared, leaving him to live in the Trash Zone. He convinces Kris to upload his mind into a powerful robotic body hidden underneath the Queen's Mansion, becoming his NEO Form. Acts as the bonus boss of Chapter 2 (and the final boss of the Snowgrave Route).
  • Defeated by ACTing: (cutting his wires): Dealmaker (Armor)
  • Defeated by FIGHTing: Puppet Scarf (Weapon)
• The Roaring Knight: Not much is known about this mysterious figure. They are the supposed creator of most chapters' dark fountains, and the one who convinced the main bosses against the heroes. This fight is very hard to win without the Shadow Mantle, to the point that it seems like a guaranteed loss. The Knight acts as the true final boss of Chapter 3, and people believe them to be the secret boss of said chapter. They cannot be defeated by ACTing.
  • "Defeated" by FIGHTing: Black Shard (Weapon)

• Hammer of Justice (a.k.a. Old Man Gerson): Gerson helps guide the heroes through the Dark Sanctuary and mentors Susie. He also has a shop in his study. Gerson was the author of Lord of the Hammer, a story heavily based on the prophecy. Acts as an NPC, shop, and the bonus boss of Chapter 4.
  • Defeated by surviving his attacks: Justice Axe (Weapon)

Minor Bonus Bosses[]

• Mike: The Mikes aren't actually the real Mike, and have been only filling for him, as Tenna becomes irritable without him. After the party enters Mike's room, they attempt to battle them out so they don't discover their secret, and rat them out to Tenna.
  • No item given upon defeat.
  • Despite no items being given, you do unlock the Mike related minigames after leaving their room.

Similarities[]

Besides possessing Shadow Crystals, the first two bonus bosses (Jevil and Spamton) share several patterns/traits in common:

• They went insane after meeting a strange individual, possibly the same one.
• They capitalize letters in most of their dialogue.
  • The names of their battle themes are also in all caps.
• They are among the few characters in Deltarune with voice lines.
  • While Spamton does not have voice lines in the conventional sense, his themes incorporate what can be assumed to be his voice.
• The word, and the concept of, "freedom" have a heavy presence with each bonus boss and their backstories.
  • The specific phrase "The air crackles with freedom." has been in each one's descriptive text rotation.
• They share a leitmotif.
• Their battles are in the basement of the party's final location (the final boss's residence) for the Dark World they are in.
• The term NEO appears in some form, being a spoken line from Jevil and a major part of Spamton NEO's form.
• Both bosses have attacks in which they physically appear as an element of the attack.
• Both bosses have attacks that involve hearts.
• They both seemingly transform into at least one of the equipment items awarded to the party on defeat.
• Both bosses (as bonus bosses) require some sort of key to access.
• Both bosses had a once-amicable relationship with a shopkeeper in their chapter (respectively, Seam and Swatch) who elaborates on part of the boss's backstory.

The trends above have been broken by the secret bosses of Chapters 3 and 4. Here are the ones that haven't, to some extent:

• Their battles have scripted dialogue and attacks that get progressively more difficult to dodge, culminating in a "final" attack that takes up the entire screen, before switching to using random attacks and dialogue.
  • Gerson's final attack does not use the entire screen, and the fight ends immediately afterwards.
• They have a unique talking sound, but no dialogue sprites.
  • The Knight has no dialogue.

Here are other comparisons between the Knight, Mike, and Gerson with Spamton and Jevil.

Similarities:[]

• Gerson's theme, Hammer of Justice, does include the freedom motif. Air Waves, one of the Mikes’ themes, also includes it.
• Gerson has the text "*The air crackles green with freedom.", showing that while yes, he is different from the first two, he is still supposed to be a secret/bonus boss.
• Gerson, along with Jevil, Spamton, Susie, Lancer and Queen, the latter three not being secret bosses, are the only ones, up until Chapter 4, to have actual laughs.
• Spamton, and Gerson both use a SOUL mode in their respective battles, with Spamton using the Yellow Soul mode and Gerson using the Green Soul mode.
  • The Mikes' way of using the Soul could be thought of as a Maus Soul mode (or Maice Soul for the Switch 2), although it doesn't have a different soul coloration.

Differences:[]

• The Roaring Knight and Eram does not have the freedom motif anywhere in their theme.
• The Roaring Knight is a required fight, though mostly scripted on a loss it is still a required step towards the end of Chapter 3.
• The Roaring Knight does not require a "key" or anything to be beaten, as the Shadow Mantle is entirely optional to beat this boss, therefore, evidence points to the Mantle game boss, aka ERAM being the real Secret Boss instead of the Roaring Knight, which is due to them being hidden inside the three visits to the S-Rank game room (or Z-Rank through the manhole.)
• The Mikes do not give a Shadow Crystal, or any item at all for winning.
• The Mikes do not have an animated backdrop for their fight, instead it being a fully black background.