Agozrael the Betrayer

Purity. Agozrael can channel the Purity inside of his body.  When he does, it will ooze out of his eyes, nose, and mouth.  He will gain 100 more hit points when he calls upon it.

Mage Hand Legerdemain. When you cast mage hand, you can make the spectral hand invisible, stow or retrieve objects, or use thieves’ tools to pick locks and disarm traps at range. You can disguise this with a Sleight of Hand check, and you can use the bonus action granted by your Cunning Action to control the hand.

Sentinel Shield. Agozrael may roll with advantage when determining his initiative.

Ring of Protection. You gain a +1 bonus to AC and saving throws while wearing this ring.

Evasion.  When you are subjected to an effect that allows you to make a DEX saving throw to take only half damage, you instead take no damage if you succeed on the saving throw, and only half damage if you fail.

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

Hexblade’s Curse. Once per short rest, as a bonus action, choose one creature you can see within 30 ft. to curse it for 1 minute (or until the target dies, you die, or you are incapacitated). Against the cursed target, you gain a +5 bonus to damage rolls, score a critical hit on a roll of 19 or 20, and you regain 5 HP if it dies.

Devil’s Sight. You can see normally in darkness, both magical and nonmagical, to a distance of 120 ft.

Pact of the Talisman. (5 Charges per day) When the wearer of your Talisman fails an ability check, they can add a d4 to the roll, potentially turning the roll into a success. This benefit can be used 5 times, and all expended uses are restored when you finish a long rest.

War Caster. You have an advantage on CON saving throws that you make to maintain your concentration on a spell when you take damage. You can perform the somatic components of spells even when you have weapons or a shield in one or both hands. You can use your reaction to make an opportunity attack to cast a spell that has a casting time of 1 action and targets only that creature.

Magical Ambush. If you are hidden from a creature when you cast a spell on it, the creature has disadvantage on any saving throw it makes against the spell this turn.

Spellcasting. Agozrael is a third-level spellcaster. His spellcasting ability is Charisma (spell save DC 15, +7 to hit with spell attacks). Agozrael has the following [Arcane Trickster and Warlock] spells prepared:
Cantrips (at will): Booming Blade, Mage Hand, Mind Sliver, Minor Illusion, Prestidigitation, Thaumaturgy, Disguise Self
1st level (6 slots): Comprehend Languages, Find Familiar,Hex, Hideous Laughter,Shield, Silent Image,Silvery Barbs

2nd level (7 slots): Darkness, Hellish Rebuke, Hex, Hold Person, Invisibility, Mirror Image, Misty Step, Shadow Blade, Shatter 

Multiattack. Purity has increased Agozrael's attack ability.  He can now make two attacks with his Unicorn Horn or Crossbow.

Unicorn Horn +3. Melee Weapon Attack: +12 to hit, reach 5 ft., 1 target. Hit: 11 (1d8 + 7) Piercing damage.  The target needs to make a CON save DC of 15.  On a failed save they take 17 (5D6 ) poison damage.  On a successful save they take half the damage. This weapon is magical. 

Booming Blade. When Agozrael performs booming blade, the target suffers 2D8 thunder damage.  If the target moves before the start of Agozrael's next turn, they suffer 3D8 thunder damage.

Purity Tendrils. When Agozrael calls upon his Purity, he increases the range of his unicorn strike to 10 ft.

Crossbow, Light +2. RangedWeapon Attack: +11 to hit, range 80/320 ft., 1 target. Hit: 10 (1d8 + 6) Piercing damage.  The target needs to make a CON save DC of 15.  On a failed save they take 17 (5D6 ) poison damage.  On a successful save they take half the damage. This weapon is magical.

Sneak Attack. Once per turn, you can deal an extra 5d6 damage to one creature you hit with an attack with a finesse or ranged weapon if you have advantage on the attack roll. You don’t need advantage on the attack roll if another enemy of the target is within 5 ft. of it, that enemy isn’t incapacitated, and you don’t have disadvantage on the attack roll.

Cunning Action. Agozrael can take a bonus action on each of your turns to take the Dash, Disengage, or Hide action.

Uncanny Dodge.  When an attacker that you can see hits you with an attack, you can use your reaction to halve the attack’s damage against you.

Silvery Barbs (see spells). You magically distract the triggering creature and turn its momentary uncertainty into encouragement for another creature. The triggering creature must reroll the d20 and use the lower roll.

You can then choose a different creature you can see within range (you can choose yourself). The chosen creature has advantage on the next attack roll, ability check, or saving throw it makes within 1 minute. A creature can be empowered by only one use of this spell at a time.

Hellish Rebuke (see spells). You point your finger, and the creature that damaged you is momentarily surrounded by hellish flames. The creature must make a Dexterity saving throw. It takes 2d10 fire damage on a failed save, or half as much damage on a successful one.  At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, the damage increases by 1d10 for each slot level above 1st.  * - which you take in response to being damaged by a creature within 60 feet of you that you can see

Agozrael has 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.  Agozrael regains spent legendary actions at the start of his turn.

Move (Costs 2 Actions). Agozrael moves up to his speed without provoking opportunity attacks.

Unicorn Horn attack (Costs 1 Actions). Agozrael can make an attack with his Unicorn Horn.  He may apply his sneak attack to the damage.