Council Guard

Battle Rhythm. When the guard lands all 4 attacks (two regular and two free) with Double-Bladed Scimitar on their turn they may make two more attacks with Double-Bladed Scimitar.

Conditioned reactions. While no enemy is within 5 ft. of the guard, they may use each unique reaction once per round (from start of their turn to start of their next turn). The guard can only use 1 reaction to any trigger.

Innate Spellcasting. The guard is a 5th-level spellcaster. Its spellcasting ability is Intelligence (spell save DC 16, +8 to hit with spell attacks). It can innately cast the following spells, requiring no components:
At will: Message, Blade Ward*
4/day either: Absorb Elements, Mage Armor, Sleep, Shield
3/day either: Arcane Lock, Misty Step, See Invisibility*
2/day either: Counterspell
*These spells are constantly active

Multi-attack. The guard may make two attacks with Double-Bladed Scimitar and a shove attack with Kite Shield.

Double-Bladed Scimitar. Melee Weapon Attack: +6 to hit, reach 10 ft., 1 target. Hit: 10 (2d4 + 6) [piercing] damage. If this hits immediately make a free Melee Weapon Attack: +6 to hit, reach 5 ft., 1 target. Hit: 8 (1d4 + 6) [slashing] damage.

Kite Shield. Special Melee Attack: make a Strength (Athletics) check contested by the target’s Strength (Athletics) or Dexterity (Acrobatics) check. If the guard wins the contest, they either knock the target prone or push it 5 feet away from them.

Shield Master. If the guard isn't incapacitated, they can use their reaction to add their shield's AC bonus to any Dexterity saving throw they make. If the effect allows them to make a Dexterity saving throw to take only half damage, they instead take no damage if they succeed on the saving throw.

Polearm Master. The guard wields their Double-Bladed Scimitar masterfully in one hand. Other creatures provoke an opportunity attack from them when they enter Double-Bladed Scimitar's reach. If this attack hits their movement speed is reduced to 0.

Bodyguard. When a creature attacks an ally, of size no larger than medium, within 5 ft. of the guard, either: with a melee attack, the guard can use their reaction to swap places with the ally and become the target of the attack, or: with a ranged attack, the guard can use their reaction to grant half cover to the ally. The guard will always use the reaction if they can.