Swamp Thing by Mark Millar #3

Plot

In these tales from SWAMP THING #161-171, a powerful force arrives on Earth to steal Swamp Thing's new elemental abilities. Then, the government sends Jason Woodrue to locate Swamp Thing in the Louisiana bayou. But Swamp Thing may be as altered as his environment-and John Constantine and the Phantom Stranger have their own plans for dealing with what he's become.