Psionic Backlash is a passive feature/reaction and Illithid Power. This feature allows a character to, when a nearby enemy casts a spell, use their Reaction to deal 1d4Psychic damage for every level of that spell.
Description
When an enemy within 9 m (30 ft) casts a spell, you can use your reaction to inflict 1d4 Psychic damage to the caster per the spell's level.
This is particularly useful against enemies casting a concentration-type spell such as some form of buff or debuff, as it does induce a Concentration check and could potentially break the spell the instant it is cast.
In the French translation the damage is said to be 1d4 + the spell level but the actual damage dealt is correct.
Brief preview
When an enemy casts a spell, can use a reaction to deal 1d4 Psychic per spell level.
