Virtual Singer Project

Crossing the boundaries of voice and worlds -- VTuber, VSinger, utaite, UTAU, DiffSinger, and more.*This project is directed by Xiel, and is a project under RE:splendor Studio. Please contact the director for collaboration and work inquiries.


"Alchemized Voice" is a virtual singer project centering on Alchemist ZETHIEL, who alters his voice to sing in different ways via "alchemization."


At the final stage of the self-alchemization, ZETHIEL realized his true awakening. Wanting to convey his heart to the world, the full emotion and nuance of his voice can be heard, as he continues to grow and blossom.


Vocal fragments across multidimensional space-time carry the memories of ZETHIEL's journey. He gathers these vocal fragments to construct synthesized vocals that he can use to expand the range of his singing potential and possibility -- and to tell the story of his fragmented past.The singing synthesis based on ZETHIEL's expressive, highly skilled, yet progressively changing vocals creates a range of musical possibility. It is his desire that he can share his emotive voice with you, as a means by which you may freely express your musical creativity and ideas.


Alcheglow Collective is a rotating collaborative group project under "Alchemized Voice" consisting of various singers.In interdimensional travel, ZETHIEL encounters many different kinds of people. His song resonates with them, creating a harmony of a new bond forged, and a precious shared memory. To all he crosses paths with, he will always remember.Check out the Alcheglow Collective playlist!

- arcdia
- Yuugen Vinny
- Opalu
- Kezo Grail
- Hanako
- Kori
- Koharu Rikka
- Chis-A
- Lio (artist)
- Pigeon (vocalsynth tuner)

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Information about the characters of "Alchemized Voice."

Alchemist ZETHIEL
Japanese Name: 錬金師ゼシエル | Renkinshi ZETHIEL
Chinese Name: 金 星天 | Jīn Xīngtiān
Birthday: 16 November
Height: 5'4" / 163cm
An alchemist whose voice is transformed across different mediums. Forging his own song, he bears a flowing and light voice that enchants the soul.Alchemist ZETHIEL is the face of the “Alchemized Voice” project. He represents the virtual singer as well as the synthesized singers.
ZETHIEL altered his own body using alchemy, and travels across time-space and alternate dimensions to explore beyond his own limits. A kind and gentle soul; and yet full of hope and conviction after breaking through a past of despair.
ZETHIEL ZERO is a young teenage boy around the age of 16-17. He specifically represents the ZETHIEL ZERO voicebanks.
He is the younger form of Alchemist ZETHIEL, before he became an alchemist to alter his own body. He loves singing and can put on a confident act, but in his heart he holds a lot of uncertainty.

Live Alchemization: “Chrysopoeia”
The live singer form of ZETHIEL. An alchemist's gear for taking on the multiverse and its memories.

First Alchemization: “Ens Primum”
The debut form of ZETHIEL. A simple yet sleek outfit that emphasizes his gentle nature, with the style of a virtual singer.

Past Alchemization: “Arcanum”
Also known as ZETHIEL ZERO, this is the younger form of ZETHIEL as a teenager. A comfortable and casual outfit -- the sweater is his favorite.
In the past, ZETHIEL was summoned to a mysterious world where music becomes magic. He was chosen, among a few others, to save the world using his singing voice. However, he wasn't strong enough to save anyone.

Past Alchemization: “Obscurum”
A form of ZETHIEL ZERO that is derived from his heart and desires for the future. It's an incorporeal form created from magic.

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Download the synthesized singers of "Alchemized Voice."All downloads: Google Drive Folder

Alchemized Voice's voicebanks featuring ZETHIEL convey his expressive singing voice, past and present. The purpose is to allow ease of use and accessibility, while capturing and preserving the nuances of ZETHIEL's voice changes through the years. The project encompasses SVS (singing vocal synthesis) and SVC (singing vocal conversion)Come and be a part of ZETHIEL's journey, and express your musical feelings with his vocal fragment alchemization.Below is a quick overview of the vocals, and beyond that are more details -- specifications, samples, and demos.

VB NameSeriesVocalUTAU (St. SVS)RVC (AI SVC)DiffSinger (AI SVS)
ZETHIEL ZEROMainenergetic mezzoVCV JP bipitchv2JP
ZETHIEL YUMainyouthful high tenorCV JPv2N/A
ZETHIEL JINMainlight expressive tenorCV JP bipitchIn DevelopmentIn Development
ZETHIEL KANAppendsolid resonant tenorCV JPN/AVoice Color for JIN
ZETHIEL HOUAppendsoft gentle tenorN/AN/AVoice Color for JIN
ZETHIEL SEIAppendcool tenor/altoCVVV JPN/AN/A
ZETHIEL FUUAppendcute bright tenorCV JPN/AN/A

An additional note: Regarding the singing corpus/database for ZETHIEL, for use in AI and similar projects, please contact the project manager Xiel to gain access. The database contains data across the mezzo-soprano, alto, high tenor, and low tenor vocal ranges, with primarily English and Japanese singing data.At some point in the future, these files shall be made publicly available, in the interest of preserving and perpetuating the voice of ZETHIEL. I hope you can use it in a way that promotes creativity, artistry, and ethical technological practices.


Date Recorded: February 2019
Type: Japanese VCV
Pitch: C4, G4*
Voice: A voice that excels in the mezzo soprano range. High energy in the upper range, and a unique voice color with a cooler tone in the lower range. Suitable for moving and upbeat melodies.
Configuration: Project Chrysalis
*spliced and synthesized from incomplete data.ZETHIEL's memory: "They all looked to me. They all needed my help. I was chosen. So why do I exist, when my voice cannot save anyone?”

Project Name: zethielzero
Version: RVC v2
Date Recorded: 2018-2019
Base Languages: English, Japanese
Data Time: 40 minutes
Recommended Range: A3-D5 (head voice up to A5)
Recommended Input Singer: ZETHIEL ZERO (UTAU)
RVC Model: HuggingFace
RVC Lite Model: Kits.AI

Date Recorded: 2018-2019
Language: Japanese
Data Time: 20 minutes
Recommended Range: A3-D5
Configuration: Kibai Hyena/Annoying Hyena

Date Recorded: 2020
Type: Japanese CV
Pitch: A3
Voice: A soft tenor vocal with a youthful color. Suitable for ballads, low-tempo songs, and soft melodic songs.
Configuration: nearsgarden
ZETHIEL's memory: "Finally, my true self begins to emerge. I can sing – I can finally sing as myself. And I need to keep singing, and keep following through with self-alchemization. I cannot stop, not now!"

Project Name: zethielyu
Version: RVC v2
Date Recorded: 2020-2021
Base Languages: English, Japanese, Mandarin Chinese, German
Data Time: 2 hours
Recommended Range: C3-C5 (chest voice) up to F5 (falsetto)
Voice: A unique and youthful voice that excels in the high tenor range. Able to belt high for powerful songs, and has a light tone with appealing falsetto for softer songs.
Recommended Input Singer: ZETHIEL YU (UTAU)
*KNOWN ISSUES: May skip/"break up" notes occasionally, although it's usually a very minor occurrence. It is recommended to run the inference again with a different cut if this occurs. An update is planned to fix this.

Date Recorded: 2022
Type: Japanese CV
Pitch: A3, C3
Voice: A natural and light tenor vocal with versatility for various genres. A beautiful flowing high range, with low range capabilities.
Configuration: nearsgarden
ZETHIEL's memory: "We're almost there. Alchemization has been going very well – I can maintain a lower pitch now. Also, in my heart, I feel a new power beginning to awaken…"


Date Recorded: 2021
Type: Japanese CV
Pitch: A3
Voice: A strong and solid tenor vocal with a resonant, bright tone. Suitable for upbeat or intense songs.
Configuration: nearsgarden

Date Recorded: 2021
Type: Japanese CVVV
Pitch: E4
Voice: A cool vocal intended for powerful songs and solid expression in the tenor/alto range, giving the impression of a mature tone.
Configuration: Project Chrysalis

Date Recorded: 2021
Type: Japanese CV
Pitch: A3
Voice: A cute and bright vocal with a refreshing tone, suitable for cheerful and upbeat music.
Configuration: Project Chrysalis

more to come...

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The “Alchemized Voice” project encompasses the character Alchemist ZETHIEL, the music featuring ZETHIEL’s voice as a virtual singer, and the singing synthesis voicebanks created from ZETHIEL’s voice.Any content posted by the official “Alchemized Voice” accounts may not be used, reposted, or reuploaded without permission – which will mainly encompass Alchemist ZETHIEL as a virtual singer.Below are the terms of use for the characters and the voicebanks. Please be aware the terms of use may update at any time.Henceforth character refers to any characters of the project, and voice refers to all free singing synthesis voicebanks released under the project. Additionally, SVS refers to "singing vocal synthesis" like UTAU or DiffSinger, and SVC refers to "singing vocal conversion" like RVC.
In relation to SVC, "inference" refers to the audio that the SVC converts via a voice model.

Section 1: General
1. Using the voice or character to promote discriminatory and abusive ideology, including but not limited to racism, homophobia, pedophilia, and more is forbidden.
2. Suggestive depictions of character, and usage of voice lyrics with mild sexual innuendo are permitted.
2a. Usage and depictions in mild and fantasy violence, emotionally heavy topics, and foul language are permitted.
2b. Sexually suggestive depictions of ZETHIEL ZERO's character is forbidden.
3. Ask for permission regarding sexual depictions; songs with overly explicit sexual lyrics.
3a. Ask for permission regarding depictions of extreme violence and gore.
Section 2: Voice
1. Usage of voice for commercial and non-commercial works is permitted.
1a. Usage of character – alongside voice – in commercial and non-commercial works is permitted.
1b. Usage of character only in non-commercial works is permitted.
2. Usage of SVS voice as inference in SVC is permitted, given the SVC model is ethically created and sourced.
2a. Usage of SVS voice as an inference for unethical, non-consensual sourced SVC models is forbidden.
3. Alteration of the voicebank configuration and files is forbidden.
3a. Redistribution of the voicebank may be permitted, particularly in scenarios where one would like to distribute and promote “Alchemized Voice” to a different scope of audience.
4. Please ask for permission regarding the use of any voice data, outputs, and files for secondary voicebank or voice model creation.
Section 3: Character
1. Alteration of the character designs in terms of clothes, hairstyle, and skin tone; free interpretation of character’s traits is permitted.
1a. Free interpretation of ZETHIEL’s gender is mostly permitted, however, the portrayal of Alchemist ZETHIEL and ZETHIEL ZERO as female characters is strictly forbidden.
2. Please ask for permission for usage of the character only in commercial works, like derivative or secondary merchandise.

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