To keep up with the relentless animosity of Malignant Monsters, you’ll need to turn their Hearts against them. Slaying Partly Corrupted enemies, a type of Malignant Monster, will drop a Malignant Heart. These can be captured by performing a ritual with the Cage of Binding, an item acquired during the Season’s Questline. Partly Corrupted enemies are an unruly sort and won’t go down easily. Trying to capture the Heart will cause the Partly Corrupted enemy to be reborn as a Fully Corrupted enemy. If defeated, these amalgamations of rot will drop a version of the Malignant Heart that can be placed into special Infested sockets in your Jewelry in place of a Normal Gem.