I watched this animated movie when I was a kid, between 1998 and 2015.
In the movie there was a race of dwarves and it was known that they didn't have hearts. When emptiness started to take over and turning things into stone, a group of I think five dwarves decided to go on a quest for a magical heart that can turn things back to normal. A young elf tags along on their journey. During the ending the heart goes into one of the dwarves chest and makes him look more feminine, the others think it's a curse so they try to kill the heart. The elf jumps in front of the arrow and gets hit; after that he falls into a lake, I think. In the end the one to have the heart is the elf.