Blend with Shadows

This spell allows the caster and the caster's carried possessions to join with ordinary shadows. This joining is so absolute that the caster no longer has a physical form. The shadow remains unmoving, despite lighting conditions— which might be a giveaway to an astute observer. The caster is aware of the surroundings, although the caster can't move or attack until returning to physical form, ending the spell. This process takes 1d3 rounds, making surprise or (for example) a backstab attempt impossible, While in shadow form, the caster can be harmed only by magical weapons or spells.