The character is Saintess from manhwa Trait Hoarder.
I don't really know what is the saintess name because it doesn't mention it in manhwa.
Character Traits:
1girl,Saintess_(Trait Hoarder),black hair,long hair,straight hair,long sidelocks,black eyes,yellow pupils,big chest,
Clothing & Accessories:
black dress,black choker,earring,long sleeves,black high heels,
Usage Note:
For best results, apply a weight between 0.7 – 1.0 to maintain character consistency and For weight between 0.8 – 1.0 to maintain clothes consistency.
Some clothing elements may not exactly match the reference images, but the differences are only minor.