Astaroth from Blue Exorcist, Also Reiji.

Reiji Shiratori (without Astaroth)

Reiji Shiratori, 1boy, solo, pale purple hair, shaggy hair, black eyes, face piercing, lip piercing, eyebrow piercing, lower lip piercing, long sleeve, red plaid shirt, white shirt underneath, dark blue body warmer with red shoulders, black skinny jeans, black shoes

Astaroth possess Reiji (half possession)

Astaroth, partial possessed, partial demonic possession, solo, 1boy, goat horns, black nail, sharp nails, sharp teeth, red sclera, black pupils, demon tail, long tongue, pale purple hair, shaggy hair,face piercing, lip piercing, eyebrow piercing, lower lip piercing, long sleeve, red plaid shirt, white shirt underneath, dark blue body warmer with red shoulders, black skinny jeans, black shoes

Astaroth possess Reiji (Full Possession)

Astaroth, full possessed, full demonic possession, solo, 1boy, brown skin, goat horns, pale purple hair, shaggy hair, battered teeth, red sclera, no pupils, long tongue, marks on forehead, mark on cheek, mark on neck, black nail, sharp nails, demon tail, ripped sleeves, red plaid shirt, dark blue body warmer with red shoulders, open shirt, ripped black jeans, barefoot

Note: Full Possession only appears in the anime. There is no image of Astaroth full possession where you can see his whole body, so you can't know how he looks bellow of his waist or how is his tail. So the prompt mentioned is a suggestion

model created by avatarAdam