Arbiter Knight Fighter Subclass_Now with Level 20 Support

Level 3.

Type: Passive

Description: Once per turn when you score a critical hit or reduce a target to zero hit points with a melee weapon attack, you receive the Blessed condition and +3m movement for 2 turns, and any allies within a 9m radius receive the Blessed condition and +3m movement for 1 turn. At level 10, the radius increases to 18m.

https://bg3.wiki/wiki/Bless_(Condition)

Chivalrous Disposition

Type: Passive

Description: You have advantage on saving throws to avoid the Frightened condition, and you have proficiency in Persuasion. At level 7, you have expertise in Persuasion. At level 10, you are immune to the Frightened condition.

Type: Reaction

Description: When attacked with a melee attack, add your Proficiency Bonus to your Armor Class, potentially causing the attack to miss.

Level 7.

Steel Resolve

Description: You and any allies within 3m have a +1 bonus to Armor Class. You must be wearing armor in order to maintain the aura.

Heroic Strike

Type: Passive

Description: You can add your Charisma Modifier (minimum of 1) to melee weapon damage.

Level 10.

Type: Passive/Free Action/Reaction

Description: Once per combat when you score a critical hit or reduce a target to zero hit points with a melee weapon attack, your Strength, Constitution, and Charisma ability scores increase by 2 for 3 turns. While this effect is active, you can use a free action on your turn to command an ally within 9m to use their reaction on their turn to make a melee weapon attack.

Level 15.

Unflappable

Type: Passive/Free Action/Reaction

Description: Once per combat when you score a critical hit or reduce a target to zero hit points with a melee weapon attack, your Strength, Constitution, and Charisma ability scores increase by 4 for 5 turns. While this effect is active, you can use a free action on your turn to command an ally within 9m to use their reaction on their turn to make a melee weapon attack.