Nightmare Walker

Incorporeal (This creature cannot be blocked by walls.)
Soulsteal (When this creature destroys another creature, put that creature onto the battlefield under your control. It is a Wraith in addition to its other types.)
Shadowborne (Whenever this creature becomes tapped, it becomes Shadowborne until your next upkeep. When Shadowborne, this creature cannot be destroyed or exiled by non-Shadowborne sources.)
{t}, Deal 1 damage to target player.