New Masks in Termina's Wrath

Carnival Mask
Obtaining: If the song of time is used to travel to the day of the carnival, this mask is sold on top of the Clock Tower for 20 Rupees

Usage: You can play unlimited free games at the game center in Ikana Canyon.

Insectoid Mask
Obtaining: During the free Anju Missions (More info on DLC on Main Page)

Usage: Lets you suck the energy out of deku sap trees and regenerate hearts

Zapper Mask
Obtaining: At the Ancient Ruins near Ikana Canyon, go to the tower and use the mask of locks to unlock it. Upon entering, several enemies and a miniboss named Auraven will appear, after defeating them, you will get the mask

Usage: This mask can be used to shut down electrical devices

Sticky Mask
Obtaining: Shoot a Raging Arrow at the goop in the Deku Palace to reveal a miniboss. Defeat it to get the mask

Usage: Leaves syrup where you walk allowing you to ger away from enemies who would be slown down by it

Upsidown Mask
Obtaining: In North Clock Town, on the 60th ingame day, the Happy Mask Salesman will set up a shop called the Mask Shop. If you buy the Mask of Mites from him, as you walk away, you will see a spaceship crash and an alien will come out. He takes a mask from the storage and flies off. You need to use the hookshot to grab onto the ship and battle him inside. When defeated, the salesman will thank you and give you the Upsidown Mask in retrn