Diablo 4 Season 3 brought a lot of dangerous and exciting new things to the world of Sanctuary. To begin new post-story challenges, players will need some Elemental Cores. Thanks to these rare items, players can challenge the new Herald of Malphas mini-bosses available as part of Arcane Tremors. The new challenges have a lot of similarities with the Blood Harvest event from Season 1, but the process for obtaining Elemental Cores is different from everything else.