Alondite is, alongside its sister sword, Ragnell, imbued with the blessings of the goddess Ashera, and is originally wielded by the first apostle, Altina, to vanquish Yune.
In the events of Path of Radiance, Alondite is first introduced in Chapter 7, wherein the Black Knight wields it against his former instructor, Greil, fatally wounding him in the process. The blade later reappears in the second part of Chapter 27, where, within the confines of Castle Nados, the Black Knight first employs it in his botched attempt to execute Ena. Ike later rushes into the building and issues him a challenge, compelling him to draw Alondite in the confrontation that ensues. As the Black Knight is defeated by Ike's hand and presumed to be killed by the subsequent collapse of Castle Nados, the sword's whereabouts thereafter are rendered unknown.
Alondite resurfaces in Chapter 9 of the first segment of Radiant Dawn, where the Black Knight, revealed to not have perished in the previous game, protects Micaiah from being assassinated by Jarod's forces with the blade as his weapon of choice. At this point, a unique characteristic of Alondite is divulged by the Black Knight, where, after Alder is slain in his vain attempt to take the fall for Jarod, he explains that the sword was not forged with the intent of slaying those who are incapable of defending themselves. This could function as a plausible explanation for the Black Knight's seeming failure to kill Ena in the previous game. As to whether this characteristic is similarly possessed by the Ragnell or not, it is, as of yet, not made known.
Alondite makes one final appearance in the second Rebirth chapter, where the Black Knight, revealing his identity as Zelgius, wields it in the showdown that he wages against Ike. Ike emerges from the battle victorious, with the defeated Black Knight expiring in the process. As Ike prepares to vacate the area, both Ragnell and Alondite will resonate with each other by glowing in unison, almost as if the spirits contained within their cores are calling out to each other. On Yune's urging, Ike will pick up Alondite, and depending on whether certain criteria have been fulfilled, the repressed memory of Ike and Mist witnessing the death of their mother at Greil's hands will be triggered. The triggering of such a flashback essentially suggests that Alondite does not just possess formidable potency as a combat weapon, but also doubles as a vessel that stores fragments of its wielder's memories or soul.
Originally known as "Ettard" in the Japanese version of Path of Radiance, this sword's name only came to be known as "Alondite" when the game was localised. The foray of Radiant Dawn further added on to the confusion, where the sword Ike wields in his debut within the game is named "Ettard" in the North American version, but referred to as "Alondite" in the Japanese version.
In the North American version of Super Smash Bros. Brawl for Wii, the Black Knight's trophy states that he wields Ettard. This is most likely attributed to the naming discrepancy earlier highlighted, where the blade that the Black Knight wields, though known as Ettard in the Japanese version of Path of Radiance and Radiant Dawn, is known as "Alondite" in the localised versions instead.