Open console (~ or ').
Type player.additem ItemCodeHere #
# = Quantity of item you want.

ItemCode = Codes listed below.

Code - Effect
Diadem of Euphoria - 0007B6B1
Nerveshatter - 0007E09D
Shadowrend (Axe) - 0009535E
Shadowrend (Sword) - 00095360