The rarity of Monstrous Reprisal is Rare, and been equipped it takes a “Bundle” slot. At this moment the item is available for trade.
Monstrous Reprisal is a skin for Riki. The skin was added to the game on September 29, 2014, it was created by Drew Carrymore.
Monstrous Reprisal has been recently added to the game, which makes it rather popular with the game community.