Voldemort has stolen the sword, Dáinsleif, from the Norse Pantheon in his quest for power.
In order to retrieve said sword, Freyja is ordered to send a squad of (can be, I dunno, 4-6) Valkyries, women with wings of pure white and covered in gleaming plate mail, in order to aid one Harry Potter in fulfilling the Prophesy and killing Voldemort. The leader of which is one Fleur Delacour.
Literally just made this prompt cause Valkyrie!Fleur.