Ten Legendary Warriors

From the Digimon Frontier, the 10 Ancient Warriors are the legendary predecessors of the 10 Legendary Warriors. Each Warrior represents one of the 10 Elements of the Digital World.

AncientGreymon
Fire

AncientMegatheriumon
Ice

AncientSphinxmon
Darkness

AncientVolcamon
Earth

AncientTroiamon
Wood

AncientMermaimon
Water

AncientWisemon
Steel

Digimon Frontier
In ancient times there was war between the human-form Digimon and the beast-form Digimon. Then one time, the Angel Digimon Lucemon appeared and brought peace to the groups. However Lucemon soon became corrupted and ruled with terror over the Digital World. It was during this time that the 10 Ancient Warriors appeared. They fought against Lucemon and sealed him in the Dark Area, the center of the Digital World, thus freeing the Digital World from his rule. However this cost them their lives. Before completely dying, they used their own data to create the Spirits that would be used by the ten Legendary Warriors when the time comes. The Spirits were then given to the three Great Angels: Seraphimon had the spirits of Wind, and Light, Ophanimon had the spirits of Fire, Ice, and Thunder and Cherubimon had the spirits of Earth, Wood, Water, Steel, and Darkness.

Island of the Lost Digimon
In the 7th Digimon movie Island of Lost Digimon, it is revealed that AncientGreymon and AncientGarurumon once fought against another evil Digimon named Onismon and sealed it on a traveling island. When Onismon was awakened again by Murmuxmon, the two ancient Warriors again appeared and destroyed Onismon, this time for good.