Diablo 4 malignant tunnels Malignant Hearts are a key factor of the Diablo four season 1 experience and Blizzard promises that there may be a way to farm them. All internationally of Sanctuary can be alternative dungeons called Malignant Tunnels. If you complete these unique regions you will encounter an Outgrowth on the end – use a crafted invoker on the Outgrowth and it will summon an...