Multiattack

The flame-scourged scion makes three tentacle attacks.

Tentacle

Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 15 (2d10 + 4) bludgeoning damage. If the target is a Large or smaller creature, it is grappled (escape DC 16). Until the grapple ends, the target is restrained, the flame-scourged scion can automatically hit the target with its tentacle, and it can't use the same tentacle on another target. The flame-scourged scion can grapple up to two creatures at one time.

Embers (Recharge 6)

The flame-scourged scion fills the area around itself with a cloud of burning embers. Each creature within 10 feet of the flame-scourged scion must make a DC 18 Constitution saving throw, taking 28 (8d6) fire damage on a failed save, or half as much damage on a successful one. The embers die out within moments.