Flamefist
Flamefist (daemonic name Tzy'y chy ikch) is a Tzeentch Daemon Prince[1a], who was born on the same world[1b] that gave rise to his fellow Princes, Bubonicus[1c] and N'Kari.[2a]
Born Werner Flamefist, he was originally a noble who secretly dabbled in alchemy and looked to Tzeentch for guidance in his efforts. While trying to turn base metals into gold, the Chaos God heard Flamefist's plea and the noble discovered a stone bathed in the Warp. This was the start of Flamefist's path to serving Tzeentch and he gathered a Chaos Cult around him soon afterwards.
During a family feud, several members of his kin discovered the Cult and in order to save the family's good name, they tried to kill Flamefist and his followers. The Fallen Noble was able to safely flee with his surviving Cultists and began a long trek to an area known as the Chaos Wastes. Once there, he would fight against other servants of the Chaos Gods in Tzeench's name for twenty years, until with the death of the Champion of Nurgle Festus, Flamefist was granted Daemonhood.[1a]
See also
Trivia
In Realm of Chaos: The Lost and the Damned Flamefist is alongside Bubonicus within the Warhammer Fantasy section as an example of the rules for Chaos Champion's gifts and warbands.[1b]
Bubonicus is then mentioned again within the 40K section "Another world has boiling lakes of blood from which spheres of fire float into the sky and spread their light across the firmament - the rule of this world is the Daemon Prince Bubonicus, formely a mortal Champion of Nurgle on one of the myriad lost worlds in the galaxy". [1b] This exact line is repeated in Codex: Chaos (2nd Edition) pg.131.[2b]
Flamefist does not have a mention within 40K specific writings but the artwork on pg. 125 by Stephen Tappin does depict a Chaos Champion upon a Disc of Tzeentch holding a plasma pistol. This artwork does not match the Chaos attributes and Chaos gifts listed on page 126.
Realm of Chaos: The Lost and the Damned specifically mentions the Warhammer World as bound by storms of magic so that it remains isolated from the other worlds of the human galaxy". [1c]