His specialty was being the only thing in the movie worth watching. Here is a simple equation to prove it:

Advent Children - Yazoo = Crap.

Quote Originally Posted by Xurts
Quote Originally Posted by Mokoto
Well i thought he was the only one who could someoen those shadow things but at the beginnign kadaj makes them disapear when they are just over cloud but i think yazoos better than loz, i dont know why though.
They have equal control over the Shadow Creepers. The Shadow Creepers are negative Spirit Energy. Negative Spirit Energy results when people die from Geostigma, and people die from Geostigma because they have Jenova cells in them. Sephiroth can control Jenova Cells, and since Kadaj, Loz, and Yazoo are remanants of Sephiroth, that means they have equal control over the Shadow Creepers.
I'd like to know where you got this piece of information that seems rather crucial to the plot...cuz I don't remember it being mentioned ever in the movie.