Waiting in the dark, the group watched as Eldrian faded into the dark of night. Using the ability of his cloak to distort the surrounding air and then covering this distortion with a darkness spell.
While his skill was not enough to hide his presence from mana sense, no light would find him. Of course, the light from a torch or spell being absorbed by a shadowy blob would be strange. But if someone only looked quickly, they would fail to notice the persistent shadow next to them.
With a little more practice, Eldrian could play with it to not give his location away. He might even one day learn how to hide the flow of mana as he commanded his weapons.
A few minutes after he left, the sounds of battle echoed in the air. In the flickering light of torches carried by the undead, the group made out a crude, massive, flying sword massacring the lower undead.
It was a chilling sight.