I had more than 10 attempts and training sessions in making v3.
Use keywords loona and hellhound in your prompt.

Bonus:
Loona has a unique set of clothing. Added two unique tags for her top wear and bottom wear to make them more distinct. Following are tags for her clothing set.
---------------| helper tags
loonacroptop | crop top, shirt, topwear
loonashorts | shorts, bottomwear

To get the strings of her crop top nicely, you can add pentagram in the prompt. Vary the emphasis, () or [], until you get them right.

There were images of her without the crop top but with the strings, which means you can have her crop top but without the strings by specifying pentagram in the negative prompt.

Others:
toeless legwear, thigh highs, stockings, legwear
fingerless gloves (should be fingerless, not just gloves)
ear piercing, ear ring eyebrow piercing, eyebrow ring notched ear

These are the tags for her red eyes with white iris and slit pupils in the dataset.
slit pupils, white eyes, red sclera

Because of the added custom tags, you can make other characters wear her clothes as well (see my comment)

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