Faultless Tracker. The seeker demon is given a quarry by its master. The quarry can be a specific creature or object the master is personally acquainted with, or it can be a general type of creature or object the master has seen before. The seeker demon knows the direction and distance to its quarry as long as the two of them are on the same plane of existence. The seeker can have only one such quarry at a time. The seeker demon also always knows the location of its master. Devil's Sight. Magical darkness doesn't impede the seeker demon's darkvision. Magic Resistance. The demon has advantage on saving throws against spells and other magical effects.
Multiattack. The seeker demon makes 2 claw attacks and one Urn of Containment if it can. Claw. Melee Weapon Attack. +7 to hit, one target, 5 ft. 9 (2d6+3) piercing damage plus the target must make a Constitution Saving throw DC 14 or suffer one level of exhaustion. This exhaustion does go away when the target gains the effects of a cure wounds spell. Urn of Containment (Recharge on 6). If the Seeker Demon struck a creature with its claws it can attempt to force the creature into the Urn of Containment it carries. The target must make a Strength saving throw DC 16 or be pulled into the urn. The creature can breathe inside the urn and it can attempt the saving throw at the beginning of its turn. After 10 failures it is stuck in the urn until the seeker demon releases it or dies.
Vicious Escape. When the seeker demon is struck with an attack it can move up to its fly movement without provoking an opportunity attack. Any creature within 5 feet of where it originally started must make a Dexterity saving throw dc 14 or take 1d6 piercing damage as its wings expand quickly.