Main character prompt:

1girl, solo, dress, purple eyes, long hair, looking at viewer, halo, 

Recommended negative prompt to get original style:

realistic

Prompt for default version: main prompt +

gloves, school uniform, neckerchief, braid, serafuku, skirt, blue serafuku, two-tone gloves, hold gun, tactical clothes, bulletproof vest, 

Prompt for swimsuit version: main prompt +

school swimsuit, blue swimsuit, one-piece swimsuit,