Castle Rudinn
Ah, do I look different? Sorry, I'm just me.
My color must've faded. Pay it no mind!Castle Rudinn, Chapter 4
The castle Rudinn[note 1] is a Darkner that first appears in Chapter 2 of Deltarune. It frequently mentions the player's chosen name for Castle Town's name, and its color changes in the later Chapters.
During Chapter 2, it resembles a typical green-colored Rudinn. In Chapter 4 onwards, the castle Rudinn becomes "faded": it has a lax expression, with the top of its head and hand being dark blue, and light blue eyelids, diamonds on its body, the tip of its tail, similar to blue versions of the Seven Flying Aces. Like other Rudinns, the castle Rudinn always has a diamond-shaped dagger.
The castle Rudinn has a friendly demeanor, often welcoming Kris to Castle Town. It appears to care for its fellow Darkners, as it keeps track of whether they have been Recruited or not. Despite this, it remains kind to Kris even if the party does not Recruit Darkners, stating that Castle Town "treasures you. Whatever you do."[1][2]
In Chapter 2, the castle Rudinn first appears near the Party Dojo once all the objects have been transferred from the unused classroom. The castle Rudinn is green, and refers to Castle Town as "[PLAYER]Town", where "[PLAYER]" is the player's name chosen during the introduction, and claims to have heard the name from someone else.[3] If spoken to again, it welcomes Kris to itself before laughing.[4] Post Cyber World, Kris can visit the castle Rudinn, causing it to acknowledge the place changing.[2] A second time causes it to hint at Castle Town's potential growth.[5]

In Chapter 4, the castle Rudinn has turned blue, and notices any changes to "[PLAYER]town" once again,[2] then comments on its state based on whether a route was completed and if a Completion FILE was used:
| Condition | Castle Rudinn's comment |
|---|---|
| Full recruits Chapter 4 |
|
| Do not use Completion FILE |
|
| Otherwise |
|
If spoken to afterwards, it says not to worry about its appearance and that its color must have faded.[6]
In Chapter 5, the castle Rudinn moves to near the exit of Castle Town. It welcomes Kris and comments on the town's state once again; its responses for "Cracked" and "Plain" states remain the same, with the same requirements for them as in Chapter 4.
If all previous enemies have been recruited, the castle Rudinn states that the town's love is "Moist", instead of "Strong", noting that it never saw a sun so dark and claims Kris made an oasis.[7] If spoken to again, it sings a short song about its faded color before seeming to question if Kris's love was "true".[8]
- ↑ Internally referred to as
castle_rudinnamong other names.
- ↑
Your Town's love is Cracked.
— Castle Rudinn, Chapters 4 and 5
Perhaps you don't treasure this place so much.
But it treasures you. Whatever you do. - 1 2 3 4
Oho. Welcome home.
— Castle Rudinn, Chapters 2, 4, and 5
Things have changed again here in [PLAYER]Town! - 1 2
Oho. Welcome to [PLAYER]Town!
— Castle Rudinn, Chapter 2
Or so I heard it's called. - ↑
Come to think of it,
— Castle Rudinn, Chapter 2
Welcome to me too! Haha! - ↑
This is a dream that grows with love and care
— Castle Rudinn, Chapter 2
Don't be afraid to dream! - ↑
Ah, do I look different? Sorry, I'm just me.
— Castle Rudinn, Chapter 4
My color must've faded. Pay it no mind! - ↑
I've never seen a sun so dark. You made an oasis for us!
— Castle Rudinn, Chapter 5 - ↑
Blue, blue, blue-be-doo. Was your love true?
— Castle Rudinn, Chapter 5 - ↑ gml_Object_obj_npc_room_Other_10 script, line 1537, Chapter 4