I think most people who are attracted to this lora have already read ninja slayer novel.

If not, I highly recommended all you guys to read it.

It would be better to add these to negative prompt:

simple background, signature, dated, text, english text, artist name, monochrome, sketch, 

Holding weapon:

katana, sheath, holding weapon, sheathed, unsheathing, 

Drinking:

drunk, alcohol, 

Smoking:

cigarette, smoking, smoke, 

Enjoy generation!