Aessilth of Air Mountain High (Young)

Sphere of Annihilation: Aessilth has one Sphere of Annihilation. Her skill with it means that when she makes an Intelligence (Arcana) check to control the sphere of annihilation, she doubles her proficiency bonus on the check. In addition, when Aessilth starts her turn with control over the sphere of annihilation, she can use an action to levitate it 10 feet plus a number of additional feet equal to 10 × her Intelligence modifier (140ft total).

Acquaintances. Once per long rest, during a short rest, Aessilth can become acquainted with a creature, with a limit of twenty acquaintances. Only creatures with the same alignment as Aessilth can become acquaintances. Aessilth can remove one acquaintance during any short rest, which can be the same one used to get a new acquaintance. This gives these abilities:

• Aessilth can easily tell non-acquainted creatures apart from acquainted ones, even when under most magical disguises. (Double prof bonus on Wisdom(Perception) for acquainted creatures)
• Creatures who are acquainted with Aessilth have an advantage on checks to remain mounted if Aessilth wants them mounted.
• Aessilth's and the mounter's self-applying external spells will also apply to both creatures if both creatures want them to.
• If both Aessilth and the acquaintance have proficiency in the same skill, all the other's non-identical bonuses are added to each other if they both perform the same INT, WIS, or CHA check for the same thing, if applicable.

Multiattack. If on the ground, Aessilth makes three attacks: one with its bite and two with its claws. If in the air, Aessilth makes two attacks, a dive and a breath attack, which is shaped like a cylinder instead of a cone. This also causes Aessilth to land.

Bite. Melee Weapon Attack: +10 to hit, reach 10 ft., one target. Hit: 17 (2d10 + 6) piercing damage.

Claw. Melee Weapon Attack: +10 to hit, reach 5 ft., one target. Hit: 13 (2d6 + 6) slashing damage.

Divebomb. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 17 (2d10 + 6) bludgeoning damage. Can only be used if Aessilth is in the air and capable of controlling a fast descent downwards. The target must make a DC 19 Dexterity saving throw or be knocked prone. Aessilth takes 1d4 damage on use. If Aessilth is mounted by a non-acquainted creature, this dismounts them. If Aessilth is mounted by an acquainted creature, they can attempt a melee attack with a range higher than 5 ft outside of their normal moves following a DC 7 Dexterity check. Aessilth is landed after this attack and can't move for the rest of her turn.

Learner's Change Shape. Aessilth attempts to magically polymorph into a humanoid or beast that has a challenge rating no higher than her own, or back into her true form. Aessilth reverts to her true form if she dies. Any equipment she is wearing or carrying is absorbed or borne by the new form if she is successful (Aessilth's choice).

As Aessilth is still learning this ability, she isn't always successful. When she attempts to use this ability, roll a d20. Then use the table below to determine whether (or how) successful she was. Most numbers will be negative. Higher negatives could indicate partial success at the DM's discretion. If the result is negative, add 1 to it permanently. A 0 means she is successful, so don't add anything. A negative number is a failure, even if it becomes 0 after the addition. If she fails, she cannot use this action for 1 hour. If Aessilth is attempting to transform into a form she has practiced at least 5 times (or is her true form), treat every number as 3 higher. (Yes, Aessilth can be trapped in a transformation temporarily) 

In a new form, Aessilth retains her alignment, hit points, Hit Dice, ability to speak, proficiencies, Intelligence, Wisdom, and Charisma scores, as well as this action. Its statistics and capabilities are otherwise replaced by those of the new form, except for any class features or legendary actions of that form.

Aessilth is also able to practice this ability. After spending 2 hours, (1 hour of which can be a short rest) roll 2d20. Add 1 to every number between the rolls. If any of those numbers are 0 before or after the addition, Aessilth changes shape and can go back at will with an action. If all numbers are 0 after practice, this ability is completely replaced by a regular Change Shape.

Breath Weapons (Recharge 5–6). Aessilth uses one of the following breath weapons.

Cold Breath. Aessilth exhales an icy blast in a 30-foot cone. Each creature in that area must make a DC 17 Constitution saving throw, taking 54 (12d8) cold damage on a failed save, or half as much damage on a successful one.

Paralyzing Breath. Aessilth exhales paralyzing gas in a 30-foot cone. Each creature in that area must succeed on a DC 17 Constitution saving throw or be paralyzed for 1 minute. A creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.

In-Flight Rescue. If Aessilth is in the air, mounted by someone she is acquainted with, and they fall off, Aessilth can use her reaction to attempt to rescue them. This requires a Dexterity check with a DC to one-fifth of the total distance in feet.