Creature Sense. The Heart is aware of the presence of creatures within 5 miles of it that have an Intelligence score of 4 or higher. It knows the distance and direction to each creature. as well as each one’s intelligence score, but can’t sense anything else about it.

The awakened tower. The awakened tower shakes and pitches on the Heart of Sorrow's initiative count. Any creature on the stairs or hanging on a tower wall at the start of the heart's turn must succeed on a DC 10 Dexterity saving throw or fall to the base of the tower. Characters who are crawling on the staircase or who lie prone on the stairs succeed automatically.

Muilti-Attack. The Heart of the sorrowing Forest can make three attacks.

Sabre Tooth Pounce. Melee Weapon Attack: +9 to hit,  1 target. Hit: 19(4d6 + 5) magical piercing damage. As a ghostly Sabre Tooth Tirger pounces on the target, it has to succeed on a DC 14 Strength saving throw, or fall 20 feet down the stairs taking (1d6) bludgeoning damage

Tentacles of the Octupus. RangedWeapon Attack: +9 to hit, range 20 ft., 1 target.
Hit: 14(2d8 + 5) bludgeoning damage. A creature hit by this attack from spectral is considered grappled (escape DC 16) , the Heart can only grapple 3 creatures at a time, the heart can use an attack to draw a grappled creature in, the creatrue has to succeed a DC 13 Strength saving throw or be reeled from the stairs and falls down the middle of the tower.

Flaming Heart. The Heart erupts in flames and  everyone within 10 feet of it has to make a DC 16 Constitution saving throw or take 13(3d6+4) fire damage or half on a successful one. A creature that fails it saving thow takes 2(1d4) fire damage on its next turn

Ink Cloud. A 20- foot-radius cloud of inky shadows extends all around the Heart. The area is heavily obscured for 1 minute, although a significant current can disperse the ink.

Stone Cold Heart.  The Heart can use its reaction to raise its AC by 3 til the end of its next turn, in which it can only take one attack action, and also gain immunity to cold damage.