I don't honestly understand why this skill isn't considered his best. Parasite infestation decks have never seemed to work well for me, where as the ability to permanently take away 800 atk from all opposing monsters over multiple turns . .is just nasty.
Agree with the use of worm bait to stack your side of the field to use this skill. Can combo in "mystic box" to give opponent a 0 atk monster.