Dealing with a white kithkin deck?

A friend of mine has a white kithkin deck, from the Lorwyn block. I've played it with a blue counter deck, a red burner, a red-green aggro-combo, and a red-green-white "Sliver Evolution" deck, but nothing gets past his first strike, vigilance kithkin soldiers. Can somebody please help me? If there's just a way to mod one of these decks instead of creating something new, that'd be appreciated—but I just need to know how to break through.