Girl, --young female
Are you a decoy damsel? -- Not Damsely, despite her tiny femaleness
(You're fading or you never were.) --Passive magic to make her ghostly
If you're a half of a something whole and have an extra half of another something, are you whole?-- -a twin (half of something) with companions (extra half)
Black turns to green. Sand turns to rust.--sand = DT