This model is trained on King wearing her outfit from 2000 (she also wore the same or similar outfit in 94, 95, 2002, XI, and other games). The dataset consisted of some screenshots of modded KOF15 and various artwork. There isn't that much artwork of King wearing this outfit, but I think the result ended up being pretty good.
Illustrious usage and notes:
Positive prompt: 1girl, KOFKing, short hair, blonde hair, jewelry, earrings, blue eyes, breasts, bow, bowtie, formal, suit, purple jacket, gloves, pants, sash, shoes
Unless you want a full body image you should remove shoes from the prompt.
I suggest adding solo to the prompt as the model tends to add additional characters to the image.
The sash can sometimes look wrong. You can try to change its weight or try to add gold sash rather than just sash.
If you add other characters to the image, they have a tendency to be clothed very similarly to King. You can remove some clothing tags and replace purple jacket with [purple::0.2] jacket instead to reduce its effect.
For full prompt examples, look at metadata for the image uploads.
https://civitai.com/models/169337/king-king-of-fighters-2000-illustriousponyxlsd15