E Commit: This attack gets -X damage or -X speed. X equals the number of cards in your opponent's card pool that share a keyword with this attack.

Does it count the keyword itself? EG If my opponent plays a throw, can I give their attack -1 or do I have to wait until they play a second throw to do anything?

I would guess that you can give it -1. I'm used to cards saying " other cards in [area]" when they exclude themselves.

Antigoth, could we get a ruling one way or the other please?

I believe it counts the attack as well, but official word wouldn't hurt.

Technically, it shares its keywords with itself...

No love from antigoth makes the Q and A borad a sad place.