If you pre-order the new expansion for Diablo III from Battle.net or link a code purchased from anywhere before the end of March, Blizzard will give you an exclusive Demon Hunter character for use in their upcoming game, Hereos of the Storm.
With Reaper of Souls launching on March 24 for PC. You basically have the week after it releases to register your code to Battle.net to qualify for the exclusive Demon Hunter character.
Heroes of the Storm is the upcoming team hero brawler (Not a MOBA, but pretty much a moba) starring a wide selection of characters from all of Blizzard’s past franchises. Heroes of the Storm is set to be released later this year for PC.