Born a Force-sensitive on the planet Lorrd, L'lacielo Sageon was discovered by scouts for the Jedi Order and taken to the Coruscant Jedi Temple for training in the ways of the Force. After years of study at the Temple's academy, Sageon was selected by a Jedi Master to become a Padawan and travel the galaxy for one-on-one training. During his training, Sageon grew in his knowledge of the Force and crafted for himself a blue-bladed lightsaber before passing his Trials of Knighthood and being elevated to the rank of Jedi Knight by the Jedi High Council.
Sageon served the Order as a Knight for many decades, serving the Jedi Temple as quartermaster, equipping Jedi for field missions for many years. However, once the Clone Wars erupted between the Confederacy of Independent Systems and the Republic, Sageon was called into active duty once more. Receiving the rank of General in the newly formed Grand Army of the Republic.
Stationed on Coruscant near the end of the war, Sageon was present when General Grievous launched a surprise attack on the capital world. Manning a fighter Sageon raced up into the atmosphere to join the fight, when word reached the Jedi that the cyborg had fled the planet with Supreme Chancellor Palpatine as his prisoner. Sageon joined several of his fellow Knights including Pablo-Jill as well as council members Agen Kolar and Saesee Tiin, in an attempt to rescue the Chancellor.
As many of his fellow Jedi broke off pursuit to rescue civilian shuttles the cyborg had fired on for the exact purpose of distracting them, Sageon, Pablo-Jill and a third Jedi continued dogging Grievous' shuttle to his flagship the Invisible Hand. Nearing the flagship as their ally was shot down Sageon and Pablo-Jill were caught in a tractor beam that tore the wings of their fighters as they attempted to avoid it and dragged onto the ship along with the vessel containing the Supreme Chancellor and General, the moment the ships were inside Sageon blew the cockpit off his Interceptor and was joined by Pablo-Jill in rushing toward the shuttle skillfully deflecting blaster bolts from the hundreds of battle droids surrounding them as they reached the ship with one of them plunging their lightsaber into the vessel's hull the General emerged, though still defending themselves against the hail of bolts the two Jedi immediately moved to engage Grievous in lightsaber combat.
As the battle droids ceased fire to avoid hitting their leader, the three combatants duel raged through the hanger despite holding their own well enough for the General to acknowledge them both as somewhat worthy opponents ultimately the old Jedi was no match for the cyborg's skill and agility and was skewered upon one of Grievous' lightsabers alongside Pablo-Jill by a brutal twin stabbing strike. The Kaleesh collected Sageon's lightsaber as well as that of the slain Ongree Jedi as trophies and ordered their bodies jettisoned into the atmosphere as a warning to the still fighting Republic soldiers.
Though the aged Lorrdian seemed to prefer helping younger Jedi prepare for their own missions he displayed skill as a pilot maneuvering his interceptor alongside several other Jedi during the Battle of Coruscant and pursuing General Grievous' escape shuttle alongside the likes of Saesee Tiin, hailed as one of the Order's best pilots, well enough to follow the cyborg directly into the hangar of his flagship. He was also able to wield his lightsaber proficiently enough to deflect multiple blaster shots from the droids in the hangar despite being heavily outnumbered, as well as duel against the General acquitting himself well enough in combat for the Kaleesh to acknowledge his swordsmanship, but in the end Grievous proved superior.
Sageon was created for the canceled Essential Guide to Episode I where it was told that he was an equipment master who equipped Jedi in preparation for the field.
L'lacielo Sageon's first name, along with the first name of fellow Jedi Waldan Bridger, is an anagram of Daniel Wallace. Originally, Abel G. Peña planned to name ancient Jedi Awdrysta Pina as "Waldan L'lacielo"; this name was changed in editing, so Peña later went on to split the anagram and use it for these two characters' first names.