It sounded like the fantasy romance novel " The Godly Doctor's Beast Taming Queen ". The female lead was the Grim Reaper. Because she had transmigrated, she had obtained a spiritual root that she could not cultivate. At the same time, she could also harvest souls. When she reforged the Yin-Yang Brush, other people would never be able to move spirit beasts in their entire lives, but there were piles of spirit beasts behind her. She received the most powerful Death God and spirit beasts of other races. There were also elves in this story. I hope my recommendation meets your requirements.