Maddening Buzzing

Any creature within 15 feet of a vescavor swarm or inside it must succeed at a DC 12 Wisdom save or be confused as it is affected under the confusion spell for 1 round. A creature that saves cannot be affected by the same vescavor swarm’s gibbering for 24 hours.  

Ravenous

Vescavors can devour nearly anything. If the swarm attacks an object or structure, the vescavors ignore its hardness if it is made of any substance other than adamantine. Additionally, every round that a creature is in the same space as the swarm, the vescavors begin devouring one object on the creature. Once the vescavors choose an item in this way, they continue to devour that same item until it is destroyed, even magic items worn or carried are affected. After dealing damage, the item takes a permanent and cumulative −1 penalty to damage rolls. If its penalty drops to −5, the weapon is destroyed. Armor reduced to an AC of 10 or a shield that drops to a +0 bonus is destroyed, other items take 4 hits and they are destroyed.  

Traumatizing

Enduring the presence of a vescavor swarm is akin to being trapped in the Abyss itself. Any creature that spends more than 3 consecutive rounds inside a vescavor swarm must succeed at a DC 10 Wisdom save or gain a type of fight madness.