Most multiplayer decks pack serious condition removal.
This may sound silly, but one of the best tactics for multiplayer (I find) is not playing a wounding shadow. Playing a wounding Shadow is putting a target on your back and saying, "kill me."
I like to let someone else have the "powerful" Shadow because he is usually the guy who people team up on and kill first.
One of the best advantages you can have is people thinking your deck sucks.
-wtk