-FL may as well be Peng xiao ran
-both about royalty (is this a spoiler lol)
-bittersweet ending (or just bitter it depends)
-ML assumed 2 identities
-FL sacrifice
-arranged marriage

Both feature marriage alliances between countries that require the princess (FL) to leave her homeland and marry afar. Both FLs are strong characters and experience heartbreak and betrayal as the plot progresses. Both share an ominous air of upcoming tragedy......