Gaia’s Blood

Xenobot neurological agent created by the Tantum Terrae to kill victims in V-cog. Quantum encrypted biological firewalls made physically harming users through the grid impossible; Gaia's Blood, engineered by Gemma Birdwhistle circumnavigated the firewall by activating a psychological exploit in the human brain whereby a subject wills themself to death by virtue of their imagination. It takes the old myth of "dying in your dream means you die in real life" to a literal level.