Cain's Stone

Origin
As mentioned in the Bible, Cain was the son of Adam and Eve and also the brother of Abel. Cain was the first human born and Abel the first to die, as Cain killed his brother out of jealousy and anger.

Effects
Causes an area effect of burning envy towards siblings. It clouds the mind, making anyone affected immediately come to the conclusion that murder is the best method. However, for every blow struck using the stone, the wielder gains a wound on their body that will never heal. Once the affected runs out of siblings, they are overwhelmed by amplified feelings of guilt and dread.