Drayfn's Bane of Excellence (TP)

Book of Ebon Tides p. 60 (Third Party)

Level
0
School
Necromancy
Casting Time
1 action
Range
30 feet
Components
V, S
Duration
Concentration, up to 1 minute
Classes
Bard, Cleric, Sorcerer, Warlock, Wizard, Fighter (Eldritch Knight), Rogue (Arcane Trickster)

Description

A creature of your choice within range must make a Charisma saving throw. On a failed save, the next ability check, attack roll, or saving throw the target makes, within the duration, that results in a roll of 20 on a d20, fails to have any effect.

Cantrip Upgrade: The number of times this cantrip can turn a natural 20 into a failure increases by one when you reach 5th level (two natural 20s), 11th level (three natural 20s), and 17th level (four natural 20s).