This item was first added during the Curse of the Drowned in 2018 along with Ghostwalkers, Lifeline, and Spectral Cutlass before being then re-added to Nexus Blitz.
The item was removed again from Nexus Blitz this time in Patch 8.17 as it was deemed that mage itemization was too strong to warrant having yet another strong choice.
UNIQUE - Touch of Death: (Passive) +15 magic penetration.
UNIQUE: (Passive) After hitting an enemy champion with a damaging ability, gain a spell shield for 2 seconds that blocks 1 incoming spell (30 second cooldown).