"Fire Fist", known as "Flame Star" (炎星Ensei) in the OCG is an archetype of FIREBeast-Warrior-Type monsters first introduced in the as Magazine Promotional Cards but from different magazines, and later expanded in Cosmo Blazer. In the OCG, every "Fire Fist" monster, except "Horse Prince", "Lion Emperor", and "Spirit", is named after the 108 heroes of Water Margin, the "108 Stars of Destiny"; the "Horse Prince", "Lion Emperor", and "Spirit" are characters from the novel, while the "Fire Formation" Spell/Trap Cards are named after celestials. Roughly a third of the heroes, the "Heavenly Spirits", have been released as of now.
As seen in the artworks, every "Fire Fist" monster has a flame which represents a monster/animal form, except "Spirit" who is a flame. Most "Fire Fist" monsters have a counterpart monster in the archetype with the same Level, ATK value and flame color. They can be seen together in the "Fire Formation" cards.
The first three "Fire Fist" monsters focus on Summoning Level 3 FIRE monsters, though they also have drawbacks. Their effects also indirectly support each other, making their respective Summons easier.
The monsters introduced in Cosmo Blazer have swarming effects initiated by sending "Fire Formation" Spell/Trap Cards to the Graveyard. But the support released in Lord of the Tachyon Galaxy have effects that initiate by sending not only "Fire Formation" Spell/Trap cards but "Fire Fist" monsters as well and their effects interact both the hand and graveyard. And the support released in Judgment of the Light have effects to Special Summon "Fire Fist" monsters from the deck and setting "Fire Formation" Spell cards when they are destroyed by battle ("Boar") or by card effects ("Deer").