The token stats are incorrect for the Breath attack of the Void Dragon Wyrmling. I think it's using an ancient dragon stats for the breath attack. Here are the actual stats from Tome of Beasts. Gravitic Breath. The dragon exhales a 15-foot cube of powerful localized gravity, originating from the dragon. Falling damage in the area increases to 1d10 per 10 feet fallen. When a creature starts its turn within the area or enters it for the first time in a turn, including when the dragon creates the field, must make a DC 13 Dexterity saving throw. On a failure the creature is restrained. On a success the creature’s speed is halved as long as it remains in the field. A restrained creature repeats the saving throw at the end of its turn. The field persists until the dragon’s breath recharges, and it can’t use gravitic breath twice consecutively. Stellar Flare Breath. The dragon exhales star fire in a 15-foot cone. Each creature in that area must make a DC 13 Dexterity saving throw, taking 10 (3d6) fire damage and 10 (3d6) radiant damage on a failed save, or half as much damage on a successful one.