Alister of doom

Special Trait Name. Enter the description for your special trait.

Spellcasting. The [monster name] is a 9-level spellcaster. Its spellcasting ability is [10] (spell save DC 19, +7 to hit with spell attacks). The [monster name] has following [class name] spells prepared:
Cantrips (at will): [eldrich blast], [fire bolt] 
1st level (7 slots): [fire ball], [descise self]  

2nd level (4 slots) [invisibility] [pyrotechnics] [see invisibility]

9th level (3 slots) [disaster blade] 

Wrath of the world ender. Melee Weapon Attack: +3 to hit, reach 5 ft., 1target. Hit: 17 (9d6+ 3 [force] damage. 

Fear of death. RangedWeapon Attack: +3 to hit, range 30/80 ft., 3 target. Hit: 16 (5d6 + 2) [phycic] damage.

Symphony of destruction: he can summon an orcestra that can give him advantage on attacks anyone else can make a Con save (DC [of Dms choosing]) if they succeed they can gain advantage of con and wisdom saves

Absorb elements.  Can cast aborb elements when hit with any elemental damage (fire,freez,lightning,electric,necrotic)

Number of legendary actions: 5

Legendary resistance (Costs 1 legendary action). Can burn one legendary risitance to become permanently immune to that type of effect

 Vacume of space (cost 1 legendary action).  The target has to make a wisdom save of 16 if fail the target is considered incasipated every turn they must make a dc saving throw or take 3d10 phycic damage for every turn the save is failed

Last shred of hope (cost 1 legendary action). Everyone withing 30 feet of the user must make a wisdom saving throw (DC [Dms choosing]) if fail they gain disadvantage of all attacks and saves for 2 turns