Alexis Doucet began as heir to the Fantasia Union's archduke, pledged to marry Marrine Kreische of the Factory Alliance. This union aimed to secure peace through the Grancrest, yet the Great Hall Tragedy shattered their wedding. Demonic interference orchestrated by the shadow organization Pandora claimed both archdukes' lives. In the aftermath, Marrine severed their engagement to lead the Alliance through rising turmoil, despite their mutual affection.

Initially gentle, poetic, and perceived as timid, Alexis revealed strategic acumen and resilience in conflict. He commanded Union forces effectively in critical engagements: a decisive land battle against a hostile lord and a pivotal naval victory against the Sea King. His calm adaptation of circular formations and tactical coordination proved vital. Alexis retained his inherent gentleness, preventing any abrupt shift toward an archetypal military commander, which fostered intense troop loyalty.

Political shifts emerged with Theo Cornaro's Altirk Treaty faction. Theo eventually mediated a renewed engagement between Alexis and Marrine, unifying the Alliance and Union. Their marriage occurred during a double wedding ceremony alongside Theo and Siluca Meletes. After three years serving under Theo's imperial rule, Alexis ascended as the Second Emperor of Leon following Theo's abdication. Marrine became his chancellor, and they parented twins, cementing their governing partnership.

From reluctant heir to military commander and finally emperor, Alexis balanced his compassionate nature with leadership demands. His relationship with Marrine, marked by initial sacrifice and eventual reconciliation, defined his narrative, illustrating commitment to duty without forsaking personal integrity.