ST Boon of the Greatwyrm

Reaching heights most dragons can even dream of, you are now a greatwyrm. Your resilience and force of will have increased to show this change and you've gained the elemental breath of most dragons. You gain the following abilities.

Breath Weapon. You gain the breath of a greatwyrm. As part of the attack action, you may replace one of your attacks with your breath weapon. You exhale elemental energy in a 300 foot cone. Each creature in that area must make a Dexterity saving throw equal to 8 + your proficiency bonus + your Charisma modifier, taking 78 (12d12) Fire damage on a failed save, or half as much on a failed save. Choose the damage type upon use. Fire, Cold, Lightning, Acid, or Poison. You can use this breath weapon a number of times equal to your proficiency bonus.

Dragon Scales. You gain the scales of a dragon. Your unarmored AC is now equal to 13 + your Constitution modifier + your Charisma modifier.

Frightening Aura. All creatures within 30 feet of you must make a Wisdom saving throw equal to 8 + your proficiency bonus + your Charisma modifier becoming frightened of you for one minute on a failed save or becoming immune to these effects for 24 hours on a successful save. Frightened creatures can repeat the saving throw at the end of each of their turns.

Draconic Movement. You gain the movement speed of a greatwyrm. You gain a walk speed of 60 feet, a fly speed of 120 feet, a burrow speed of 60 feet, and a swim speed of 60 feet.