Heaven Blossom Quest/Spoiler

*Enter Shadowthorn (for instructions on how to get there, go to the Shadowthorn page).
*You will encounter some Elves. Go down the ladder closest to you.
*Make your way towards the star on the map. You will only encounter some Elves here, and maybe a lured Elf Overseer.
*Open the Barrel to receive your reward, a Heaven Blossom.