Shadow Crystal

Shadow Crystals, so called because you can only see their shadow.

Seam, Chapter 2

The Shadow Crystal (JP: シャドウジェム Shadow Gem), formatted as ShadowCrystal in the inventory, is a reoccurring secret Key Item in Deltarune. They are crystals containing the power of a Lightner's "lost dreams" and are obtained from defeating Shadow Crystal bosses. They can be given to Seam, who explains that the crystals may be found with powerful enemies and that they are invisible but still cast a shadow.

Upon collecting the second one from Spamton NEO and bringing it to Seam, they explain that the next foe that carries one of these may be completely unbeatable without an item known as the Shadow Mantle, which they intend to give to the party, but cannot find.

After acquiring the third crystal from the Knight and delivering it to Seam in Chapter 4, they state that they can make a peculiar item that the party would "quite enjoy" with two more Shadow Crystals. This, coupled with other dialogue Seam has if the player misses a crystal after previously collecting one during their playthrough, implies there are only five Shadow Crystals available to collect in total, as Seam seemed to completely dismiss the plan after missing one of them.

If the party has not defeated a previous Shadow Crystal boss in the current SAVE file, but in the SAVE slot which the current game progress loaded or started from, the Shadow Crystal boss has been defeated and their defeat was recorded by saving in their respective Chapter (as presented by the Shadow Crystal indicator on the bottom-right of the Chapter Select menu), they can find its Shadow Crystal and the equipment by inspecting the hole in the cliff to the left of Castle Town. This allows the Shadow Crystal and an equipment from a Shadow Crystal boss to be shared to any other SAVE files once the boss is defeated, if there exists vacancy to rearrange save file slots or save to multiple slots.

The Glass (JP: ガラス) is the Light World form of the Shadow Crystal, separate from the Ball of Junk. It cannot be dropped, as "the thought of discarding it felt very wrong". Using the Glass makes Kris see through it, either seeing Susie glaring at them if she is following in Chapter 2, Noelle leaning against them and whispering in Noelle's House in Chapter 4, or otherwise seeing through their hand.

Flavor text

Using the Shadow Crystal in a Dark World seemingly shows Kris the Light World's equivalent of the current location. Using the Glass in the Light World shows an illusion of unknown meaning. Both of these effects quickly pass, and cannot be repeated.

Shadow Crystal

• You held the crystal up to your eye.
  • For some strange reason, for just a brief moment... [First use]
    • You thought you saw toys strewn on the floor. [Card Kingdom]
    • You thought you saw the computer lab. [Cyber World]
    • You thought you saw the television get smashed to pieces. [TV World]
    • You thought you saw the lobby of the church. [Dark Sanctuary]
    • ...but, it must've just been your imagination. [Follow-up]
  • [Flower Kingdom]
    • For some strange reason, for a brief moment, it looked like...
    • Everyone else disappeared...
    • ... and you saw Noelle smiling at you, with arms full of flowers.
  • ... but nothing happened. [Second use, or Castle Town]
• It doesn't seem very useful. [Subsequent uses]

In the Dark Sanctuary, the Shadow Crystal interacts with the prophecies appearing throughout.

Dialogue when used in a room with a prophecy tapestry

• You held the crystal up to your eye.
• For some strange reason, no matter how you look...
• The prophecy's text does not warp in the crystal's lens.

Dialogue when used in the room with the Last Prophecy

• You held the crystal up to your eye.
• For some strange reason...
• The prophecy's text does not warp in the crystal's lens.
• You shook the crystal...
• However, nothing changed.

Glass

• You looked through the glass.
  • For some strange reason, for just a brief moment... [First use]
    • You thought you saw through your hand. [Default]
    • You thought you saw Susie glaring at you, coldly... [Followed by Susie, Chapter 2]
      • But when you moved the glass away,
      • You see her looking at you, smiling and making a rude gesture.
    • You thought you saw Noelle close against you, whispering. [Noelle's House, Chapter 4]
      • You put the glass to your ear...
      • ... of course, that didn't do anything...
    • You thought you saw your mother holding someone else. [Chapter 5]
    • You thought you saw Susie in a far-off window, unkempt and glaring. [Aborted Weird Route, Chapter 5]
  • ... but nothing happened. [Second use]
• You held the crystal up to your eye. [First use, Chapter 3; Unused]
  • For some strange reason, for just a brief moment...
  • You thought you saw Undyne frozen in ice.
• It doesn't seem very useful. [Subsequent uses]
• (You didn't quite understand why...) [Attempting to drop, Chapters 1&2]
  • (But, the thought of discarding it felt very wrong.)
• (For some reason you felt like if you throw it away...) [Attempting to drop, Chapters 4&5]
  • (It would be like throwing away someone's... ???)
  • (... But you didn't fully understand it.)

Gallery

• 
  Shadow Crystal received from defeating Jevil
• 
  Shadow Crystal received from defeating Spamton NEO
• 
  Defeating Spamton NEO in the Weird Route for a Shadow Crystal
• 
  Shadow Crystal received from defeating the Knight
• 
  Shadow Crystal received from defeating the Hammer of Justice
• 
  Shadow Crystal received from the Castle Town cliff
• 
  Shadow Crystal received from defeating Pink

Trivia

• There exists a currently-unused item called the PureCrystal. Its item description, "The shadow purified by the cat", may suggest that it is a Shadow Crystal which was purified by Seam.
• A "peculiar book" that can be found in the 2nd Sanctuary mentions a "fallen star" making "rivers with its tears" until something that "looked like glass" was formed out of the "bitter water", suggesting a possible connection to Shadow Crystals.
• If a Shadow Crystal is carried over from a previous Chapter, the Use message for Chapter 3 can appear before the Chapter's Shadow Crystal is obtained, foreshadowing Tenna's defeat at the Knight's hands.
• As of Version 1.04, it is impossible to see the drop text in Chapter 4 on PC because the code that checks whether a Light World item is a weapon or not will always at least return the ID for the Pencil, causing all items to display "(Recently, seems like weapons can't be thrown away so easily.)" when attempting to drop them in Chapter 4.
• In the Japanese version, for Seam's Chapter 4 dialogue that is triggered if the first two Shadow Crystals were already given to them, but the party was defeated the Knight while also having the Shadow Mantle, the Shadow Crystal's Japanese name, シャドウジェム ("Shadow Gem"), is mistranslated as シャドウクリスタル ("Shadow Crystal").

Version history

Game edition	Version tag	Changes
Chapter 1&2 Demo	v1.06	Allowed the Glass to properly appear in the inventory if Kris has a Shadow Crystal.
	v1.07	Jevil gives the Shadow Crystal immediately when defeated. New flavor text was added for using the Shadow Crystal or Glass in Chapter 1.
	v1.19	Introduced an indicator of attained Shadow Crystals per SAVE file and Chapter to the Chapter Select screen.
Deltarune	v1.00	Collecting Jevil's Shadow Crystal and one equipment from the cliff of Castle Town requires Jevil has been defeated in the corresponding save slot, instead of any one.