Atissan

Keen Hearing and Smell. The Atissan has advantage on Wisdom (Perception) checks that rely on hearing or smell.

Pounce. If the Atissan moves at least 15 feet straight toward a creature and then hits it with a claw attack on the same turn, that target must succeed on a DC 14 Strength saving throw or be knocked prone. If the target is prone, the tiger can make one bite attack against it as a bonus action.

Multi-Attack. The Atissan makes two attacks: one with its claws and one with its bite.

Soul Devourer. If the Atissan kills a creature it rends their soul out of the body instantly. The creature cannot be revived by any means and another Atissan spawns out of the body of the dead creature.

True Evasion. The Atissan's heightened awareness allows it to nimbly dodge many forms of what would otherwise be doom. If the Atissan has to make a dexterity saving throw the Atissan does so with advantage and if it passes it takes no damage, otherwise it takes only half damage.

Bite. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 10 (1d10 + 5) piercing damage.

Claw. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 7 (1d8 + 3) slashing damage.

Deform. When the Atissan is hit by a ranged attack it can use its reaction to deform its body of darkness, creating a hole through its body which the attack harmlessly passes through. Doing so still damages the Atissan, as reforming the body takes some of its energy. The Atissan takes 4 (1d4 + 2) necrotic damage after using Deform.