Valve has removed the hero Warlock from the active hero pool in Dota 2 matchmaking. The developers have not officially commented on the situation. However, this action follows reports of a bug that allowed players to gain experience at an extremely rapid rate with this hero.
The bug is reportedly linked to the interaction between the Black Grimoire aspect and the item of the same name. By exploiting a specific sequence of actions, players could infinitely use the artifact, leading to incredibly fast hero leveling.
The initial bug related to Warlock (and Witch Doctor), which involved the unintended transfer of unique hero items, was reported by the Telegram channel voidsploit as early as April 12th. This earlier exploit, as well as the newly discovered experience bug, remained unpatched, ultimately resulting in Warlock`s temporary removal from matchmaking.
Finley Holt