Fuse with ambient darkness, vanishing from detection.
You cannot be targeted directly by ranged weapons and spells (area attacks can still hit you as well as melee attacks). You are effectively hidden even if the enemy is aware of your general position.
Might result in an opposite roll against awareness skills if opponents are looking for you (mostly outside of combat). Notice that you are not silenced in any way from this spell.
Your attacks have the unnoticed (and perhaps even more depending on position) attack roll modifier (+20).
Your defence has the concealment modifier. Enemies who saw you before they shadowmeld can attack with a -10 penalty.