Alexander is the heir presumptive to the kingdom of Lycia. A challenger to the throne appears, trying to win public support by claiming that the current royal family is "tainted" with dragon blood. To Alexander's surprise, the rumors turn out to be true, as he is able to channel the power of the Ice Dragon through a long-forgotten family relic.
(Alexander can only use swords throughout, although once promoted, he is classified as a flying unit and can cross mountain and water terrain.)