Devil's Sight. Magical darkness doesn't impede the imp's darkvision.

Bite. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 7 (1d6+4) piercing damage plus 3 (1d6) acid damage and the target must succeed on a DC 12 Constitution save or contract the disease Devil Chills. 

Devil's Eye. By touching a willing creature, the accuser devil can telepathically convey anything it has seen in the past 24 hours. This shows visual memories only, not sound or any other sense. It can transfer one hour of vision in a single action. 

Devil Chills. Disease. Symptoms begin 1d4 days after infection. While suffering from the disease, the victim gains a level of exhaustion that cannot be removed. At the end of each long rest, the victim may make a Constitution save to end the disease. On a failed save, the victim gains another level of exhaustion that cannot be removed.