Causal Knight

The path of the Causal Knight is one that you have walked countless times before, and yet, you have never walked at all. Such is the paradoxical nature of those who are placed on this path. Only one has ever been chosen by the greater wills of the universe to become a knight scattered across time: you. Stripped of the individuality of your mortal nature, you must hold together yourself, and every version of you that was and never was, lest your mind scatter throughout the infinite.  As each part of your broken mind wanders on it's own accord, the new collective that was once the singular you will learn to control this newfound power. However, it is for the same reason that you will require a hardened mind; you will perish should you fail to comprehend and control your infinite fragments. Walk the paths, warrior, that you, and you, and you might come together to correct this broken world. 

Infinite Existence

The travels that you and your echoes have taken have revealed many small secrets to you. When you choose this subclass at 3rd level, you gain two benefits:

You gain proficiency in one skill of your choice.

You are able to speak, read, and write one language of your choice.

Causality Shift

At 3rd level, you are able to quickly phase your body out of and back into the timeline. As a reaction to taking damage or being targeted by a ranged attack, you can use this feature to reduce the damage you take by half, or give the ranged attack disadvantage on it's attack roll. You are able to use this feature as many times as your fighter level divided by 4, and cannot be used until after you take a short rest. 

Temporal Correction

At 7th level, if you or a creature within 20 feet of you takes damage, you can use your reaction to summon one of your echoes to counterattack. The creature must make a Dexterity saving throw. The save DC for the throw is equal to your Fighter level + your Strength modifier. On a failed save, the creature takes force damage equal to the damage die of your weapon. On a successful save, the creature takes no damage. You must be able to see both the attacker and the creature taking damage to use this feature, and you cannot be restrained, incapacitated, or prone. The damage die used doubles at 12th level, and triples at 16th level. This feature can only be used again after a short rest. 

Ergodic Determination

At 10th level, you may project yourself into varying positions across the battlefield, manifesting the infinite possibilities of the chaos around you. When you take the attack action, you may choose to teleport up to 5 feet into an unoccupied space you can see. If you successfully attack, you may choose to teleport again. If the target is unable to see you, you may teleport up to 10 feet and attack with advantage. 

Convergence of Intent

18th level Causal Knight feature

At 18th level, you can call upon multiple versions of yourself to wreak havoc on a foe, harnessing the power of the infinite. When you hit a creature with an attack, you can cause that attack to trigger this feature. If you choose to do so, 5 perfect copies of yourself appear around the enemy. The copies share your stats and weapon, and each immediately makes the attack action. Each copy deals force damage equal to your weapon die and fighter level. You may use this feature once per long rest. 

In addition, when using your Action Surge, you summon two copies that use the Attack or Help action simultaneously.