What to wear: The easiest way to go for a (spoiler alert!) Henry/Vecna/One costume is simply finding a white dress shirt, white dress pants, and a dark belt to embody One in his more harmless era. You could also try pulling off an actual Upside Down Vecna costume by acquiring a mask or getting creative with some lycra and foam — either way, Henry/Vecna/One is sure to be a fun Halloween villain to embody for the night.