This mask was used by Lady Shiva when she murdered the Armless Master. After this, she gave the mask to Bruce Wayne when he was triying to recover his abilities to reclaim the mantle of the Bat. The Mask of Tengu made it easier for the Disciples of Armless Master to recognize the "killer" and confront Bruce to avenge their master's death. This was all part of Shiva's training, but after defeating all the Disciples, Bruce recovered all his skills and dropped the Mask in favor of his old Batsuit.
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