* Rex Goodwin: The leader of the Dark Signers, and the main antagonist of the series.
* Devack: The first Dark Signer to appear, and a former friend of Yusei Fudo.
* Roman Goodwin: Rex's brother, and the second Dark Signer to appear.
* Kalinin: A Russian Dark Signer who utilizes a dark card to manipulate others.
* Misty: A mysterious woman who appears as the fifth Dark Signer.
* Z-one: A powerful being from the future who orchestrates the events of the series. He isn't technically a Dark Signer, but he has a strong connection to them.
* Antinomy: An enigmatic figure who appears alongside Z-one, and is also connected to the Dark Signers.
It's important to note that while the Dark Signers are the primary antagonists, Z-one and Antinomy are more complex characters with their own motivations.