Luminous Valentine from That Time I Got Reincarnated as a Slime / Tensei shitara Slime Datta Ken
When I tested it some different checkpoint and LORA's it seemed to work well with this LORA.
LORA weight 0.7 works great, but feel free to adjust the strength to your liking.
The settings for the Pony version can differ from the 1.5 version
Prompts that I usually used:
long hair, grey hair, (heterochromia), red eye and blue eye, black skirt, white collar, hair ribbon, black arm guards, short sleeves