Nuryt

Nuryt is a substance which is poisonous to reapers, but harmless to normal cores. It works by disturbing the strings, because of which normal healers aren't able to fix the condition induced by it. Reversed Nuryt works in an opposite way and is able to fix soul strings.

Nuryt is healer's blood and will only crystalize once the Healer, who was the original carrier of it dies.

Because of its string-disturbing properties, Nuryt is often used in production of weapons against reapers.