The rarity of Artisan of Havoc is Mythical, and been equipped it takes a “Bundle” slot. At this moment the item is available for trade.
Artisan of Havoc is a skin for Clockwerk. The skin was added to the game on June 16, 2014, it was created by OniLolz.
Artisan of Havoc has been recently added to the game, which makes it rather popular with the game community.