Phantasmal killer

Phantasmal killer, originally known as Carbury's killer, was an illusion spell that created a phantasm of an attack by the most fearful creature the victim could imagine.

Effects
This spell reached into the victim's subconscious, pulled out the most horrifying creature he or she could imagine, and attacked with it using an illusion only the victim could see clearly    (the caster saw only an indistinct shape   ). The victim had one chance to disbelieve the illusion and be free from the nightmare    (although for an early version of this spell, timely applications of remove fear or cloak of bravery could give additional chances to resist  ) or else the imaginary beast pursued and attacked relentlessly until the spell ended or victim died of fright. The spell also ended if the victim or the caster were rendered unconscious,  the caster's concentration was broken by some means, or the victim had a constitution strong enough to survive the mental onslaught and the resulting physical damage.

For the older versions of phantasmal killer, certain circumstances could raise or lower the chances of resisting the mind beast. If the victim was caught completely off guard against an attack, he or she was much more likely to succumb. If the victim had previously been a target of this spell and survived, he or she was less likely to believe the illusion again. If the target was an illusionist, then the chances of disbelief were even greater. And finally, if the target was wearing a helm of telepathy they were much more likely to shrug off the attack and could even turn the tables on the caster, forcing the attacker to defend against his or her worst nightmare creature or die.

Components
Only verbal and somatic components were required to cast this spell.

History
This spell was invented by the Netherese arcanist Carbury in –903 DR (2956 NR, during Netheril's Age of Discovery). It was known as Carbury's killer and was a fourth level spell in the school of Inventive magic.