This is the mask of the villain, Death Gun in the show Sword Art Online.
Step 1: Build the Goggles
Use cardboard to make the goggles. Cut circles, and then glue onto earpiece.
Step 2: Build Jawline
Cut cardboard pieces and glue them together. Make sure to shape the cardboard to your jawline.
Step 3: Add Nose
Use cardboard to make the nose extend through the middle from the goggles to the jaw.
Step 4: Cheeks
Hot glue wide pieces of cardboard to fill in the cheek area.
Step 5: Forehead
Make a line of cardboard that fits over the top of your head, then glue it to the earpiece of the goggles.
Step 6: Connecting
Use a strip of cardboard to connect the head strap to the goggles.
Step 7: Forehead 2
Fill in the gaps of the forehead like you did with the cheeks.
Step 8: Teeth
Add teeth and circular respirator. Cut the teeth out and four circles. Glue two sets of circles together and then glue them over the jaw.
Step 9: Paint and Eyes.
Paint the mask and then glue red tissue paper to make the eyes.