Geddoe serves as the leader of the 12th Unit of the Harmonian Southern Frontier Defense Force. Although quiet, he commands a strong presence as a mercenary. His colleagues also trust him deeply despite his unwilling to talk about his past. He joined the force some seven or eight years prior to the outbreak of the War of the Champions. In the past, he had sustained an injury to his eye, requiring the use of a patch.
Years ago, he was a close friend of the Flame Champion, helping the original Fire Bringer to fight against the Holy Kingdom of Harmonia 50 years ago. He would end up inheriting the True Lightning Rune. Following that war, he travelled the world, through many unnamed countries before becoming a mercenary and hiding his identity. Once he was ordered by the Holy Kingdom of Harmonia to investigate the rumours of the Fire Bringer, his situation began to change.
Geddoe and his unit would follow clues to the Great Hollow and the Karaya Village. He was able to determine that there was a conspiracy inciting war between the Zexen Federation and the clans of the Grassland. Realising that the Masked Man was involved, he followed his trail to Le Buque before travelling to Budehuc Castle and eventually the Flame Champion's Hideaway.
Although he harboured some resentment towards the Flame Champion, the realisation that Luc was planning to obtain the True Runes, prompting a massive Harmonian invasion, solidified Geddoe's will to protect the Grassland as a member of the Fire Bringer. During the War of the Champions, he would temporarily lose his True Lightning Rune to Luc, but knowing the consequences of what would happen if Luc's plans came to fruition, he struggled against his own mortality, reclaimed his rune and helped to bring peace to the Grassland.
Following the war, Geddoe was able to return to his duties in the Southern Frontier Defense Force thanks to Sasarai but was still undecided about his future, carrying the True Lightning Rune once again.
- Geddoe's weapon upgrades as Crow, Geese, Wild Geese.
- Geddoe learns the unique skills Parry, Freeze and Magic Repel. He tends to do well in any area, as a potential Flame Champion.
- He gets the highest rating in Fire Magic of any possible Flame Champion, although most tend to keep him with Lightning, which he is still best at.
- Geddoe participates in the spectacular Mercenary B attack with Queen, Ace. Joker and Jacques.
- Geddoe's age is revealed as 112, although he had apparently stopped aging somewhere in his 30's.
- Gensosuikoden Kiwami Encyclopedia, page 300