Invading and killing hosts in PVP, aiding hosts against bosses through cooperation, and killing the red-eyed Old Hunters in the Hunter's Nightmare will grant players a Vermin while the rune is equipped.
Equipping the Impurity rune allows players to summon special NPC Hunters which too are a part of The League and are connected in-lore, those Hunters are:
The summoning Messengers of these NPC Hunters are different in color. Whilst most have a pinkish red hue, the League Confederate Hunters have a blood red color to it. These Hunters will also spawn into the world performing the "League Oath" gesture and will have the title of "Confederate" as a prefix.
(Read the Old Hunter Bell page to learn which bossfights players can summon these League Confederates into)
- Players wearing the Impurity Oath Rune will be hostile towards other summons wearing conflicting Oath Runes, such as the Radiance Oath Rune, and the Hunter Oath Rune.
- The rune resembles a crucified human being bleeding from the wrists.