An amazing prologue and intriguing premise make this series starter a riveting YA fantasy read, particularly among fans of ultrapowerful "chosen one" protagonists. Legrand's opening chapter is brilliant and sets the page-turning tone -- a baby, an evil queen, mentions of a lost love, and a battle between said queen and an even more mysterious angel. That's a compelling start if ever there was one. Once the story rewinds (for Rielle) and goes forward (for Eliana), it occasionally gets tripped up with more action than world-building (and definitely more steamy romance and sex positivity than is typical in YA books outside of, say, Sarah Maas' bestsellers), but readers will still want to barrel through to figure out what's happening and what turns Rielle into the character we meet in the opening pages.
Between the two main characters, Rielle is the more likable, even though readers know where her story "ends" from the start. At times she seems a bit too overwhelmed by desire for Audric (and even the sexy angel speaking in her mind) than worried for her world's future, but she is, after all, a teenager in love. Audric, for his part, is an earnest, handsome hero without any stereotypical bad-boy edge. That edginess is reserved for Simon, who's scarred and cryptic and has a complicated attraction to Eliana. The plot is super simple if excised from all the action sequences (a seven-part trial in the past, a rebel mission in the present). But younger readers unused to timeline changes may find it difficult to understand if they're rushing. Even after 500-plus pages, readers may not fully grasp the scope of what's at stake for Eliana's timeline, but they'll be ready for more of the Blood and Sun Queens in Book 2.