The Making of: Ralsei Cosplay

The Making of: Ralsei Cosplay

Tl;Dr: 18 hours sewing rush means having fun making Ralsei’s Cosplay!

Greetings everyone! Now that Deltarune Chapter 2 is out I thought it might be the time to make an entry on how I made Ralsei's cosplay back when Chapter 1 got out!

As usual we'll go through the History behind the cosplay, how every piece got made, their challenges, anecdotes and final notes! This is Arkan writing, enjoy the pictures and many words!


Deltarune Ralsei Cosplay Undertale how to make


A Bit of History

As a heads up: Undertale and Deltarune got a very special place in my heart. They mean a lot and having a sequel coming out on Spo-oktober 2018 I had to oblige and lean into cosplay!

Ralsei is best boi and it stuck with me. So what do you do when the crafting fever gets you? That's right: an 18 hours sewing rush. Please note that with Chapter 2 coming out at 2am in France, you can guess bedtime was at 7.30am trying not to think about what next cosplay I would make. No promise on Butler Ralsei NOT being made next year..!



The robe was and still is easy to make. Finishes though, the second and later versions of the cosplay got them better. It is the cosplay that got me into taking care on the exterior and overall look of what I made so later on I could make the best clothes for myself. It was not a great first robe, but it was an important and decisive piece into my cosplay journey. In a way?

Deltarune Ralsei Cosplay Undertale how to make

To keep with "screen accuracy" (as much as you can gather with sprites) I altered patterns I had bought to better fit the visuals of Fluffy Boy. This served as a test before making Evy's Robe!

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Embroidering is not easy without the right tools and as a first experience: it was very challenging but rewarding. Later on I upgraded and got an embroidering circle and some stabiliser for making the black pixelated heart. The pictures speak for themselves.

Other than that it's pretty easy in its own way. Long straight almost unending lines, nightmarish lining and sleeves. The usual sewing time, right?



First time making a hat teaches you a lot on how to draft 3d shapes and how to hold them without the fabric folding and having wires and nonsense everywhere. The brims are padded with iron-on and thin dense foam. The pointy ear bits were first triangular shapes sewn straight on top of the fabric before having them made into pointy cones sewn in a circular shape on the top side of the brim.

Deltarune Ralsei Cosplay Undertale how to make

They are pretty straightforward to make, given patience and enough pins. Head circumference is tricky to handle on such patterns and a fit-all size never truly fits with straight fabric. I later made the pattern digital so I can work on various sizes easily and quickly!



The first time making a scarf! Pretty easy but having the right length of this material is now so hard. Sourcing for fuschia fabric is so difficult now that it has fallen out of fashion. The scarf itself is warm, VERY warm. Like, it is so long and broad that even in winter in the full cosplay walking outside to a convention I had to open the robes to vent some heat out. It's also really comfy and I like to wear it anytime I can!

 Deltarune Ralsei Cosplay Undertale how to make scarf



The whole outfit was made in an 18 hours rush. Was it smart? No. Dangerous? Well yes given how little sleep I gathered before. Was it worth it? Yes!

Although I/We now take time for both quality and health, making +12 hours shifts every once in a while gets me that boost I crave: the need to make the best pieces I can in the moment and learn in the process.


Final Notes

Back in 2018 on this rush I had the bright idea to record the crafting process on timelapse mode and post it on YouTube because why not! Next thing you know it has now more than the average 30 views I was expecting and people are just so, so nice! 


V2 of the cosplay was made with Marie being around and SHE took the updated pictures as well as helping me with the makeup! While I am not very comfortable with how I look, I’m very happy that we got to spend some time in her room and the blackscreen, teaching her how to use the camera and making punny jokes! 

I hope someday to make myself an updated version and get back to what we once called “Conventions not being canceled because of a pandemic”. That would be nice!

Deltarune Ralsei Cosplay Undertale how to make robe scarf hat

I believe that is all I have to say about Ralsei’s Cosplay! I hope you got to enjoy the pretty pictures! Have a nice day and until next time! 


1 comment

  • Lauren

    Hi there! Could you share the link to where you got the pattern for the robe?
    Thank you 😊

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