From publisher blurb:
Death Has Never Been So Beautiful
Elves unlike you've ever seen them before.
Thousands of years studying their art has made them into deadly warriors. True defenders of their people, the Blade-Sirens use the graceful technique of bladesong to turn their foes into mincemeat! With this hybrid class, you'll get to play as one of the mythological blade-sirens who wield sword and spell in a beautiful dance of death.
This class is loosely based on the Forgotten Realms prestige class, bladesinger.
If you love Forgotten Realms and have ever wanted to see the bladesinger made into a full fledged Pathfinder class, this book is for you!