Brumren, the Tyrant Knight

Lay on Hands. Brumren has a pool of healing power than can restore 115 HP per long rest. 

Divine Sense. Brumren always knows the locations of all fiends, celestials, and undead within 60 ft. that are not behind total cover.

Divine Smite. Whenever Brumren hits with a melee attack, he may expend one spell slot to deal 2d8 extra radiant damage to the target, plus an extra 1d8 for each spell level higher than 1st (max 5d8), plus an extra 1d8 against fiends and undead (max 6d8).

Divine Strikes. Whenever Brumren hits with a melee attack, he deals an extra 1d8 radiant damage.

Channel Divinity: Guided Strike. Whenever Brumren makes an attack roll, he may use this ability to gain a +10 bonus to hit. He can only do so before knowing the result of the roll. (2 uses)

Spellcasting. Brumren is a 20th-level spellcaster. His spellcasting ability is Charisma (spell save DC 20, +12 to hit with spell attacks). Brumren has the following paladin spells prepared:
1st level (5 slots): Armor of Agathys, Bless, Command, Compelled Duel, Divine Favor, Shield of Faith, Wrathful Smite

2nd level (4 slots): Aid, Hold Person, Spiritual Weapon

3rd level (3 slots): Aura of Vitality, Bestow Curse, Blinding Smite, Daylight, Fear Revivify

4th level (3 slots): Banishment, Death Ward, Dominate Beast, Stoneskin

5th level (3 slots): Circle of Power, Cloudkill, Destructive Wave, Dominate Person, Geas

Aura of Protection. All creatures of Brumren's choosing within 30 ft., including himself,  gain +6 to all saving throws while he is conscious.

Aura of Conquest. While Brumren is conscious, all frightened creatures within 30 ft. of him have their speed reduced to 0 and take 11 psychic damage if starting their turn in his aura.

Aura of Intimidation. Creatures of Brumren's choosing within 30 ft. that are size Large or smaller and are immune to being frightened lose that immunity. Instead, they have advantage on saving throws against being frightened.

Aura of Courage. Brumren and all creatures of his choosing within 30 ft. are immune to being frightened.

Scornful Rebuke. Whenever a creature hits Brumren with an attack, the attacker takes 6 psychic damage if Brumren is not incapacitated.

Exceptional Weapon Master. Brumren can make an additional attack if he lands a critical hit or reduces a creature's HP to 0. Before he makes a melee attack, he can choose to take a -5 penalty to the attack roll to add +10 to that attack's damage.

Channel Divinity: Conquering Presence. As an action, Brumren forces all chosen creatures within 30 ft. to make a DC 20 Wisdom saving throw or they become frightened for 1 minute. Creatures may repeat the saving throw at the end of each of their turns. (2 uses)

Lay on Hands. As an action, Brumren can touch any creature to restore any number of HP remaining in the Lay On Hands pool, or 5 HP to cure a disease or neutralize a poison affecting the creature.

Cleansing Touch. As an action, Brumren can end one spell effect on himself or any willing creature that he touches. If he uses Lay on Hands, this can instead be used as a bonus action. (6 uses)

Multiattack. Brumren makes 2 attacks with his Halberd.

Halberd. Melee Weapon Attack: +14 to hit, reach 10 ft., one target. Hit: 14 (1d10 + 8) magical slashing damage. 

Breath Weapon. Brumren exhales an icy blast in a 15 ft cone. Each creature within the cone must make a DC 17 Constitution saving throw or take 25 (5d8) cold damage.

Opportunity Attack. Creatures that leave Brumren's reach provoke an attack of opportunity, giving Brumren one melee attack against them.

Polearm Master. Creatures provoke attacks of opportunity when they enter Brumren's reach (10 ft). Brumren can also use the end of his Halberd as an additional attack (+14 to hit, reach 10 ft. Hit: 11 (1d4 + 8) magical bludgeoning damage) when making opportunity attacks.

Sentinel. Creatures provoke attacks of opportunity even if they take the disengage action. Their speed becomes 0 for the rest of their turn. Creatures within 10 ft. of Brumren that attack creatures other than him provoke attacks of opportunity.

Brumren has one legendary action that is used immediately if Brumren can see, hear, or tell that Hank, Hope-Touched has died in combat with him. This legendary action counts as a second reaction, and does not occur if Brumren directly causes Hank, Hope-Touched's death.

Godlike Conqueror (Costs 1 Action). Brumren becomes an avatar of conquest, channeling as much power as he can from Bahamut himself, causing him to sprout spectral, draconic wings and a godly aura, as well as healing himself for half of his missing HP. For 10 minutes, Brumren gains immunity to radiant damage, necrotic damage, bludgeoning, piercing, and slashing damage from nonmagical attacks, resistance to all other types of damage, and gains advantage on all saving throws and checks. He gains truesight 60 ft., 30 ft. of flying speed, 10 ft. of walking speed, and cannot be removed from his current plane of existence against his will. Brumren can make one additional attack. Attack rolls of 19 and 20 are treated as critical hits.

If, after 10 minutes, Brumren is still alive, he loses his godly form and suffers four levels of exhaustion. These can only be removed by long rests. Brumren becomes incapable of taking this legendary action after using it, or if Hank, Hope-Touched dies without Brumren's knowledge.