Gullveig from Fire Emblem Heroes.

Trigger: GullveigFEH1, two-tone hair, yellow eyes, pale skin, long hair, gold trim

Default: GullveigOG, single horn, snake hair, leotard, detached sleeves, wide sleeves, high heels

Brave: GullveigBRV, gradient hair, gemstone, horn, braid, leotard under clothes, suspenders, bare shoulders, gradient clothes, pants, high heels

Summer: GullveigSUM, single horn, hair flower, swimsuit, criss-cross halter, sarong, high heel sandals, cleavage, fruit

Her horn in her brave form can be a bit tricky to pull of, you'll often get the normal horn instead of the rainbow one, but the gems will appear around her head.