Iron Flame does a decent job of raising the stakes of Rebecca Yarros’ Empyrean Series, but Violet and Xaden’s story in the Fourth Wing sequel highlights a challenge facing future books. Violet and Xaden start Fourth Wing as natural enemies, with Violet’s mother being responsible for squashing the rebellion Xaden’s father once led. As Violet and Xaden come to know one another, however, their relationship swings in the opposite direction. Despite their best efforts to avoid falling for one another, Violet and Xaden get together in Fourth Wing.
https://screenrant.com/violet-xaden-iron-flame-story-challenge-empyrean-series/