Seliph is the son of Sigurd and is the main character in the second half of Fire Emblem: Seisen no Keifu. As an adult, Seliph seeks revenge on the nobles that framed his father and had him killed. Just like his father, he is an extremely talented warrior, a very loyal and honorable man, and has an extremely strong sense of justice.
Seliph was chronologically born in Agustria (of Grandbellian heritage) in the early part of Seisen no Keifu. During his infancy, his mother Diadora was captured by the aristocrat Manfloy, leaving him without a mother. Eventually, as his father Sigurd approached Barhara, Seliph was sent to Isaac under the protection of Oifaye and Shanan. He was also raised by Adean, who acted as a surrogate mother. Seliph was taught how to fight by Shanan, and grew up with several other children, including Delmud, Lester, Lana, Skasaha and Lakche.
Seliph grew up in the town of Tirnanog in northern Isaac, along with Skasaher and Lakche, the children of Ayra, and Rana, Aideen's daughter. Due to his father's exploits and the corruption of the Grandbell Empire, Seliph came to be known as the 'Child of Light'. He joined the Liberation Army led by Shanan, but was eventually cornered by Danan of Dozel. Desperate, Seliph and his friends struck out of Tirnanog to retaliate. Helped by timely reinforcements led by Oifaye along with Lester, Rana's brother, and Delmud, Lachesis' son, Seliph gained an upper hand. He met Levin afterwards and was asked to protect Yuria, a mysterious girl whom Levin has been taking care of.
He soon gained the help of either Johan or Johalvier (Danan's sons, only one of them joins out of their love with Lakche), as well as Arthur and Fee. With this combined strength, Seliph gained enough power to drive away Danan from Isaac. Levin told him more about Sigurd and suggested that they join up with Shanan, along with Seliph's cousin Prince Leif of Lenster.
Meeting up with Shanan, Seliph was also joined by a thief named Patty. Seliph made haste to Alster where he met and helped Leif, Finn and Nanna to defeat Blume. Along the way, he's joined with Tinny, Arthur's sister; Ares, Eltoshan's son; and Lynn, Sylvia's daughter. Together with his new allies, Seliph drove away Blume from Alster, and then set off in pursuit of his fleeing adversary. Reaching Manster, Seliph finished Blume for good, but had a premonition of an upcoming battle against a certain 'Yurius'. In Leif's favor, Seliph pushed through Thracia, getting the help of Sety, Fee's brother.
During the ensuing war against Thracia, Seliph was joined by Hannibal, Thracia's Great General, as well as Corple, Lynn's brother, and Althena, Leif's sister. Eventually, after subduing Thracia, Seliph set his sights to Grandbell, to claim what's rightfully his. But as he arrived to the Miletos district, Yuria went missing.
En route to Chalphy, Seliph had a hard fight against the nefarious Prince Yurius and his close ally, Ishtar. However, for some reason, they pulled back. Before he reached Chalphy, Seliph spotted dark mages pursuing a bishop and several children. He cut through the mages and rescued the group. Afterwards, Seliph was given Sigurd's sword, Tyrfing, as a token of gratitude.
Eventually, he faced Alvis, Sigurd's killer, in the castle of Chalphy. In the end, Seliph came out triumphant and avenged his father. Upon returning to the cliff where he received Tyrfing, hemet the ghosts of Sigurd and Diadora, telling him that the war is not over. Seliph himself didn't quite understand why he felt empty even though he avenged his father.
Seliph's real trial came when he had to face the Grandbell dukedoms in order to unify them. On the way, Levin told him the story of the previous war and Seliph learned that Yuria was necessary to end the battle and was also his sister. But Yuria was already brainwashed by Manfloy by the time he arrived. Seliph had his friends hold off Yuria while he went off to Velthomer, facing the culprit behind all the chaos, Manfloy. After killing him, Seliph managed to snap Yuria back to her senses. After bringing her to Velthomer, unlocking the sacred scroll of Narga, Seliph fought Prince Yurius, who was possessed by Loputousu. After killing Yurius, he is then installed as the new Emperor of Grandbell, possibly married to an empress, along with Yuria by his side.
Fire Emblem: Awakening
Seliph appears in Fire Emblem: Awakening as a DLC character. His Awakening character class is Swordmaster. Awakening also marks the first time that the character has appeared in a Fire Emblem game that received an officially localized release outside of Japan.