AMU

Demonic Vessel: In the scarecrow he is in, he gains fire immunity and necrotic immunity

Curse of AMU: AMU can curse someone with terrible headaches, nightmares and exhaustion.

Possession: AMU goes into someone and inhabits them, the user must make a wisdom or constitution saving throw, if they do not get over 20, they are possessed until a radiant spell hits the character or they succeed a saving throw. note: AMU will be taking the damage (unless it is physical) when possessing. he cannot posses any type of holy character, like a cleric. if they are something like a oathbreaker paladin, they can still be possessed.

Demonic scream: the players must make a wisdom saving throw (success 20) if failed, the targets are afraid, this is unless they are a cleric of the life or light domain. 

Breath of Hellfire: AMU fires fire from his mouth, this attacks in a 50 ft radius fully around him. all in the radius must make a constitution saving throw of 16. if failed, the target takes 1d20 fire damage.

Aura of Hell: the battlefield is filled with a mist that will start burning the players if they are not resistant or immune to fire damage. the burning does 2d8 fire damage every turn. this though can be countered by using a sort of water, or wind spell that will either blow away the mist or fight it with a whole bunch of water vapor.

demonic touch: When he possessed someone, he will naturally move 10 feet to the nearest enemy every turn, this concludes their turn unless they are able to touch a player, when they can they will touch and instantly kill the person, this will not count if they have radiant soul or some sort of divine ability, this includes divine soul sorcerers. 

Hiding in the tree: He immediately goes to a tree after someone takes him out of possessing someone. this will make him invincible until he comes out of the tree, this will only be 1-2 turns, depending on how close someone is to the tree. 

Unspeakable Power: He speeds around and bounces off trees, every person must make a dexterity saving throw higher than 20 or take 4d20 Force damage.

As a bonus action, AMU can yell a call to summon Democabras from the woods. he will rarely do this though.

whenever hit with an attack hat he is vulnerable to, he will either back away 10 feet opposite of the attack or will scream that does 1d4 damage to every enemy, he will only scream if he is under 400 health.

he has 3 legendary actions per round. These cannot be used when possessing someone.