Dark Angel Olivia from Granblue Fantasy. The Key outfit isn't entirely right but close enough (the white part is not training properly). I included the shorter hair variant from Bahamut and Shadowverse as well for her grand outfit.

Prompts

Default (Grand)

gb_dao, da_olivia, orange hair, long hair, sidelocks, black horns, red eyes, gradient wings, feathered wings, purple wings, orange wings, hair ornament, black dress, turtleneck dress, bikini armor, black armor, sleeveless dress, white underbust, lace trim, gold trim, black gloves, elbow gloves, red belt, miniskirt, pleated skirt, black skirt, gold knee pads, armored boots, black boots, thigh boots

*Replace long hair with medium hair for the shorter hair look

Fallen Angel of the Key

gb_dao, key_olivia, orange hair, long hair, sidelocks, one-side up, black horns, red eyes, gradient wings, feathered wings, purple wings, orange wings, hair ornament, gold trim, white shirt, black armor, bikini armor, red underbust, red overskirt, black skirt, petticoat, asymmetrical legwear, black thighhighs, lace thighhighs, gold knee pads, gold heels, keyblade, holding keyblade

Swimsuit

gb_dao, swim_olivia, orange hair, long hair, sidelocks, black horns, red eyes, mini wings, gradient wings, feathered wings, purple wings, orange wings, hair ornament, hair flower, hibiscus, white jacket, sleeveless jacket, layered bikini, black bikini, white bikini, bikini skirt, white heels, strappy heels