Contract Marriage: Rewritten

Laniakea, a royal princess shunned by her family due to her weak elemental power, accepts a proposal from Hyperion, an imperial prince without political backing, purely to escape her homeland. Their marriage contract includes a missing clause regarding childbearing, leading to three quiet years where Hyperion stays at the borderlands while Laniakea prepares for an eventual divorce. However, after all the other princes die, Hyperion ascends to the throne and unexpectedly demands they have an heir immediately rather than end their marriage.