Avassh

Alien Mind. If a creature tries to read Avassh’s thoughts or deals psychic damage to it, that creature must succeed on a DC 22 Intelligence saving throw or be stunned for 1 minute. The stunned creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.

Legendary Resistance (3/Day). If Avassh fails a saving throw, it can choose to succeed instead.

Magic Resistance. Avassh has advantage on saving throws against spells and other magical effects.

Regeneration. Avassh regains 20 hit points at the start of its turn. If it takes radiant damage, this trait doesn’t function at the start of its next turn. Belashyrra dies only if it starts its turn with 0 hit points and doesn’t regenerate.

Teleport. As a bonus action, Avassh can teleport up to 30 feet to an unoccupied space it can see.

Multiattack. Avassh makes two attacks with its claws and uses its Infestation Spores if it is avaliable.

Claw. Melee Weapon Attack: +14 to hit, reach 5 ft., one target. Hit: 17 (3d6 + 7) slashing damage plus 10 (3d6) poison damage

Infestation Spores (Recharges 5-6). Avassh releases spores that burst out in cloud fills a 20-foof-radius sphere centered on her, and it lingers for 1 minute. Any flesh-and-blood creature in the cloud when it appears, or that enters it later, must make a DC 15 Constitution saving throw. On a failed save, the creature is infected with a disease called the spores of Avassh and also gains a random form of madness (determined by rolling on the Madness of Avassh table) that lasts until the creature is cured of the disease or dies. While infected in this way, the creature can't be reinfected, and it must repeat the saving throw at the end of each turn, ending the infection on a success. On a failure, the infected creature's body is slowly taken over by fungal growth, and after three such failed saves, the creature dies and is reanimated as a spore servant if it's a type of creature that can be (see the "Myconids" entry in the Monster Manual).

Avassh can take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at a time and only at the end of another creature’s turn. Avassh regains spent legendary actions at the start of its turn.

Claw. Avassh makes one claw attack.

Spawn Fungi (Costs 2 Actions). 2 Vine Blights well up from the ground near Avassh, appearing within 20ft of Avassh and moving directly after it in the intiative order.

Mind Control Spores (Costs 3 Actions). Avassh releases spores that burst out in a cloud that fills a 20-foot-radius sphere centered on it, and it lingers for 1 minute. Humanoids and beasts in the cloud when it appears, or that enter it later, must make a DC 19 Wisdom saving throw. On a successful save, the creature can't be infected by these spores for 24 hours. On a failed save, the creature is infected with a disease called the influence of Avassh for 24 hours. While infected, the creature is charmed by Avassh and can't be reinfected by these spores.