My assassin has an encounter power called Shadow Jack, it reads like this:
Hit: 2[W] + Dexterity modifier damage, and you shift 1 square into the target’s space and remain there until the start of your next turn. While there, you are insubstantial, you move with the target (this movement doesn’t provoke opportunity attacks), and any melee or ranged attack that misses you hits the target instead, unless the target is the attacker. At the start of your next turn, you slide 1 square to a square adjacent to the target.
My question is this: If they make a ranged attack while I'm "hiding in their shadow" (i.e. in their square), do I get an opportunity attack on them?