Wu is infected with a disease causing him to become a werewolf, so it's not a full Wesen transformation, but close enough. To bring you up to speed, the main character (Nick Burkhardt) recently had a baby with his onetime mortal enemy (Adalind Schade).

Does Wu get cured?

Fortunately, Rosalee has seen these symptoms before and quickly makes a potion to cure him. Nick arrives just in time to help them make Wu drink it. The cure unfortunately causes him to have hallucinations of everyone's face melting off.

Does Wu die in Grimm?

Wu (Reggie Lee) and Hank (Russell Hornsby) were killed by Zerstorer.