Shadow Dancer

A graceful yet menacing warrior, Shadow Dancers are masters of altering shadows and turning them into physical manifestations of a fighting style. 

Shadow Fighter

Beginning when you choose this archetype at 3rd level, you gain the ability to create a shadow doppelganger of yourself as an action on your turn. This doppelganger has all of your stats, proficiencies, feats, features and items, but only half of your modifiers (Rounded down). The doppelganger has health equal to 8 + your constitution modifier + your fighter level and 12 armour class. This doppelganger cannot speak, but it can understand any languages you know.

This doppelganger always has initiative equal to your initiative minus one. It can perform any actions, bonus actions, reactions, etc, that you can. When this doppelganger dies, you cannot remake it until you complete a long rest. The doppelganger has resistance to poison and necrotic damage, but a weakness to radiant damage, and it is immune to being charmed or frightened. 

Shadow Shield

At 7th level, you can command your shadow to create a shield. The shadow takes 1d8 damage, and grants you or an ally within 15 ft of the shadow +2 AC for the next 5 minutes, or until the shadow dies. Your shadow also gains advantage on attacks with finesse weapons when below half of it's max health (Rounded down).

Second Shadow

Starting at 10th level, you can summon a second shadow fighter to assist you. Both of your shadow fighters also gain the ability to defend an ally for 1 minute, following any commands they issue instead of your own.

Shadow Dance

At 10th level, you and your shadow have reached a higher level of synchronization. As an action on your turn, you can use your shadow's next action to make a powerful combination attack on a foe with a finesse weapon. This attack deals 3d6 damage from you and 2d6 from your shadow.

Critical Finesse

Starting at 15th level, your weapon attacks with a finesse weapon score a critical hit on a roll of 18–20.

Shadows of Battle

At 18th level, you have mastered control of your shadows. You gain the ability to summon a third shadow, and all of your shadows have their armour class become yours. Your shadows also gain 1d8 of psychic damage on all of their attacks.