Substance

Drawing upon wisps of shadow and darkness you may add actual substance to an illusion you have casted or recognized as an illusion. Doing so makes the illusion more difficult to detect granting anyone who touches the illusion disadvantage on investigation checks to recognize it. If the Illusion would attack or use the substance behind it to deal damage, the target must make a Wisdom save: on success they recognize the illusion, on fail they take 2d10 Psychic damage.

At Higher Levels. When you cast this spell with a 4th level spell slot or higher the damage increases by 1d10 every additional level.