The following section contains information from a previous version of StarCraft II which is no longer valid.
StarCraft II beta files indicate that Zeratul once had a "phase mine" ability.[1]
This was absent in the final release of Wings of Liberty. Map editor files indicate another ability, "Shadow Clones", which would create two shadowy copies of Zeratul to aid him in battle. The clones dealt half damage and took double damage from enemies.[2]