In the classic Madhouse Studios style (with Yutaka Minowa character designs) from the 1993 film Ninja Scroll.

• Weight around 0.1-0.7/8 --lower the weight even more if it's too much

Characters:
Not trained on names.
Add brown/black/yellow eyes and eyelashes in the prompt for more accuracy.
Jūbei - (1boy, solo, male focus, dark skin, brown eyes, eyelashes, lips (neg-red lips), manly, brown hair, messy hair, long hair, long bangs, ponytail, Japanese clothes, holding weapon, holding sword, katana, glaring, serious, frown, rice hat, split rice hat, samurai, fighting stance, battle, open mouth, teeth, clenched teeth (Include: 'perfect teeth' - if need be)
Kagerō - (1girl, black hair, short hair, straight hair, parted bangs, eyelashes, brown eyes (or) black eyes, red lips (or) lipstick, purple headband, forehead jewel, ninja, gloves, fingerless gloves, short kimono, knife, pale skin, loose hair strand)
Genma - (black hair, short hair, straight hair, long sideburns, pixie cut, bangs, eyelashes, black eyes, manly, muscular, pectorals, thick arms (possibly), glaring, chin, serious., smile, smirk, dark skin.
Possibly more accuracy for him with prompt -> Red theme.
Tessai - Stone Man - (rock, bald, cracked skin (you could also try stone skin or rock skin), manly, muscular, (note: male focus may turn him into Jubei)
Benisato -Snake Woman- (black hair, long hair, straight hair, nihongami, half updo, loose hair strand, eyelashes, yellow eyes, arched bangs, red lips (or) lipstick, smile, kimono, fingernails, ????, bare shoulders, snake, pale skin)
Extra: Dragon (helps produce the snake sometimes), tentacles (mostly cursed though).

Other characters may appear but less so.
Might also be able to get...
Dakuan - (old, old man, straw hat, rice hat, hakama, haori, staff)
Mujūrō Utsutsu - Blind Samurai - (eyelashes, closed eyes, black hair, long hair, straight hair, arched bangs, haori, hakama, hakama skirt, holding sword, katana, bamboo forest)

LANDSCAPES: No humans, scenery, indoors, outdoors, grass, valley, snow, desert, moon, building, architecture, east asian architecture, water (also include: Inverted reflection), sky, cloud, bloom (can help for the overall style), fireflies, field, flowers, tree, waterfall, plant, star (sky), wooden floor, mountain, fantasy setting, landscape, etc.

MONSTERS: Monster/Tentacles/Snake/Scales - (2m Karras works pretty well for them) and can make some pretty cursed looking stuff since it's not really trained on any monsters; Just the snakes crawling on Jubei/snake woman, etc.
Blue, Red or Green theme for a possible base (not completely necessary but may help) - (Trained more on blue theme)
blue theme - Night, Night Sky, Dark --
^ And for a better chance at lightning effect: Electricity, bloom, Monochrome (and/or 'spot color')
green theme- Bamboo Forest, Kagero, Jubei, hetero, (or -- 'couple, hug, resisting, forced, molestation')
red theme- Building, Burning, (Fire, Flames, Blaze -- not in the prompts though and Jubei/Genma may show up)

NEGATIVE:
sepia
high contrast
scar
headband
forehead jewel
nihongami (<- geisha hairstyle)
chronmage (<-samurai hairstyle)
monochrome
nude
naked
nipples
3D
realistic
hetero
blood
blood on face
rice on face
pillarboxed
anime coloring
broken
topless -- (female characters like to generate ???? sometimes)
painting/oil painting -- (if it's too 'messy')
muscular
pectorals
open clothes
open kimono
thick/buff -- (if the males are too beefy)
2girls
2boy/3boys/6boys/Multiple boys
malformed sword
weapon
katana
facial mark
2000s style
black border
white border