Sorcerer L25 with access to Elderday Magic
Legendary Resistance:
If Ashavanti Gagan Akaval fails a savings throw, three times per long rest she can choose to succeed instead.
Elemental Adapt
Any Fire damage by Ashavanti Gagan Akaval ignores resistance to fire damage of the chosen type. In addition, when she rolls damage for fire damage, she treats any 1 on a damage die as a 2. Any fire immunity is dealt as minimum damage.
Aether birthright
Ashavanti Gagan Akaval calls upon her draconic birthright and shifts through the Spaces emerging in any location in the Places she chooses. Using the cosmological phenomenon pervading Existence, Ashavanti Gagan Akaval cannot fail when moving and can take up to eight willing creatures within 30" of her.
She can use her Aether birthright up to nine times between short rests. Any area that is subject to null-teleport magic, will force her to appear at the adge of the null-teleport zone. She can then use her Aether birthright to enter the null teleport zone the following turn, automatically suffering one level of exhaustion, dealing only half damage for four rounds, all actions taken with disadvantage and all actions against her are taken with advantage.
Destructive Urge
Nine times between long rest, Ashavanti Gagan Akaval can reroll any damage she deals and choose which of the two she will use.
Shivan Boon
Once every nine days, she can grant one creature the boon of adding d8+1 fire damage to a melee attack once per long rest. No more than nine creatures can have the boon in effect at any one time.
Multiattack: Ashavanti Gagan Akaval can use her Terrifying Presence. She then makes three attacks: one with her bite and two with her claws. All creatures within 10" of Ashavanti Gagan Akaval are effected by her Fiery Death ability on initiative count of 20 (she she choose to use it). Bite: Melee Weapon Attack: +22 to hit, reach 20", one target. Hit: 2d20 + 13 piercing damage plus 4d12 fire damage. Claw: Melee Weapon Attack: +22 to hit, reach 15", one target. Hit: 2d12 + 13 slashing damage. Tail: Melee Weapon Attack: +22 to hit, reach 30"., one target. Hit: 2d12 + 13 bludgeoning damage. Terrifying Presence: Each creature of Ashavanti Gagan Akaval's choice that is within 180" and aware of her must succeed on a DC 24 Wisdom saving throw or become terrified for 1 minute. A teerrified creature suffers not only from the frightened effect, but also takes all actons with disadvantage and all actions against it are made with advantage. A creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. A success does not provide immunity from future savings throws. Fire Breath (Recharge 5-6): Ashavanti Gagan Akaval exhales fire in a 150" cone. Each creature in that area must make a DC 26 Dexterity saving throw, taking 26d8 fire damage on a failed save, or half as much damage on a successful one. Fiery Death: All creatures within 10" automatically take 2d6+6 fire damage on initiative count 20, should she choose to do so. Call of the Empress; As an action Ashavanti Gagan Akaval can summon once per day a Red Dragon. If the Red Dragon is an adult, she gains one level of exhaustion, if the red dragon is an ancient, she gains two levels of exhaustion. Additionally she is considered staggered for a number of rounds equal to the level of exhaustion she has taken.
Ashavanti Gagan Akaval can use a bonus action to cast any cantrip.
Insolence
If any creature approaches within 5" of Ashavanti Gagan Akaval, she can make an attack of opportunity with her claws that also causes the creature to make a DC 25 strength savings throw or be knocked prone, or knocked back up to 15" (Ashavanti Gagan Akaval choice)
Ashavanti Gagan Akaval take 3 Legendary Actions, choosing from the options below. Only one legendary action can be used at a time, and only at the end of another creature's turn. Spent legendary actions are regained at the start of each turn. Detect: She makes a Wisdom (Perception) check. Tail Attack: She makes a tail attack. Wing Attack (Costs 2 Actions): The dragon beats its wings. Each creature within 20" of Ashavanti Gagan Akaval must succeed on a DC 27 Dexterity saving throw or take 17 (2d10 + 11) bludgeoning damage and be knocked prone. Ashavanti Gagan Akaval can then fly up to half its flying speed.
On initiative count 20 (losing initiative ties), Ashavanti Gagan Akaval takes a lair action to cause one of the following effects: