Diablo 4 Season 13 hides one of its most striking cosmetics behind a secret endgame challenge: the Howling Mouth of Madness portal skin. This reward is tied to the Echoing Hatred activity, where you need to follow a specific shrine sequence and then defeat a special goblin to claim the portal Diablo 4 Items. The first step is getting access to Echoing Hatred. You need the Trace of Echoes, which...