Aldrag

Legendary Resistance (3/day). If Aldrag fails a saving throw, he can choose to succeed instead.

Tactical Wit. Aldrag gains a bonus to his initiative rolls equal to his INT modifier (+5)

Cloak Of Protection. You gain +1 bonus AC and saving throws while you wear this cloak.

Armor of Fire Resistance. Aldrag has resistance to fire damage.

Action Surge. Aldrag can take one additional action on his turn. This can be used 1 times per S/R.

Great Weapon Fighting. Aldrag can reroll a 1 or 2 on damage dice with melee weapons wielded with two hands.

Combat Superiority. Maneuvers enhance an attack in some way. Aldrag has 4d8 superiority dice per S/R.
Disarming Attack. When Aldrag hits with a weapon attack, he can expend one superiority die to add it to the damage roll and to disarm the target if it fails a STR saving throw (DC 17)
Precision Attack. When Aldrag makes a weapon attack roll, he can expend one superiority die to add it to the roll before or after the roll but before any effects are applied.
Trip Attack. When you hit with a weapon attack, you can expend one superiority die to add the total to the damage roll, and if the target is Large or smaller, it must make a STR saving throw (DC 17). On failure, you knock the target prone.

Spellcasting. Aldrag is a 6th-level spellcaster. Its spellcasting ability is INT (spell save DC 17, +9 to hit with spell attacks). Aldrag has following wizard spells prepared:
Cantrips (at will): chill touch, frostbite, toll the dead
1st level (4 slots): absorb elements, shield, sleep
2nd level (3 slots): invisibility
3rd level (3 slots): counterspell, dispel magic, intellect fortress

Multiattack. Aldrag can make two Flame Tongue Greatsword attacks or cast one wizard spell from the spell list.

Flame Tongue Greatsword. Melee weapon attack: +9 to hit, reach 5ft., one target. Hit: 10 (2d6 + 5) slashing damage plus 7 (2d6) fire damage.

Arcane Deflection. When Aldrag is hit by an attack or fails a saving throw, he can use his reaction to gain +2 bonus to his AC against that attack or +4 bonus to that saving throw. When he uses this feature, he can't cast spells other than cantrips until the end of his next turn.

Mage Slayer. When a creature within 5ft. of him casts a spell, he can use his reaction to make a melee weapon attack against that creature.

Aldrag can take 2 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. Aldrag regains spent legendary actions at the start of his turn.

Attack. Aldrag makes a Flame Tongue Greatsword attack.

Second Wind. Aldrag regains (1d10+6) HP.

Misty Step (Costs 2 Actions). Aldrag teleports up to 30 feet to an unoccupied space that he can see.

Acid Breath (Costs 2 actions). Aldrag exales acid in a 15-foot cone. Each creature in that area must make a Dexterity saving throw, taking (3d6) acid damage on a failed save, or half as much on a successful one.