Base effect: All enemies within 30 feet that are maintaining or initiating a performance-based ability, casting a spell, or using a spell-like ability must make a concentration check (DC 31). If the check is successful, they instantly lose one round of performance, a spell slot or prepared slot of the same level as the one they cast, or one daily use of that spell-like ability (if it is usable at will, they can’t use it for 1d4+1 rounds). If they fail the check, they also waste their action as the ability or spell fails.
You manifest the ravenous power of the void to devour your enemies. One enemy within 30 feet suffers one or more negative levels. If they are immune to negative levels, or if they succeed at a Fortitude saving throw, they instead suffer negative energy damage. These negative levels are temporary for 24 hours, after which the target must make a new saving throw for each negative level they suffered. On success, the negative level is lifted; on failure, it becomes permanent.
Weak Refrain: the target suffers 1 negative level, or 5d6 damage.
Intermediate Refrain: the target suffers 1d4 negative levels, or 20d6 points of damage.
Strong refrain: the target suffers 2d4 negative levels, or 30d6 points of damage.