The Kazier was the original secret leader of the Crimson Dawn criminal syndicate whose role would be ultimately filled by the former Sith Lord Darth Maul.
In a Tweet he posted on his Twitter account, screenwriter Jon Kasdan shared some details about The Kazier:
By the first draft of Solo: A Star Wars Story, The Kazier served as the true leader of Crimson Dawn behind the shadows. Through unknown reasons, however, the character was ultimately scrapped from the film's story and was replaced with Maul, who first appeared in the 1999 film Star Wars: Episode I The Phantom Menace.