The Astral Plane is the realm of thought and dream, where visitors travel as disembodied souls to reach the Outer Planes. It is a great silvery sea, the same above and below, with swirling wisps of white and gray streaking among motes of light like distant stars. Most of the Astral Sea is a vast, empty expanse. Visitors occasionally stumble upon the petrified corpse of a dead god or other chunks of rock drifting forever in the silvery void. Much more commonplace are color pools — magical pools of colored light that flicker like radiant, spinning coins.

The Astral Plane is meant to be neutral territory, but some entities want to use its properties to prey upon the material plane. Abyssal creatures lure and drag creatures and their souls from other planes into the Astral Sea, where they are harvested for energy. That lifeforce will cause the Abyssal and Material planes to crash into the Astral, allowing demonic forces and old gods to seize deathless power and dominate the multiplanar universe. 

Astral Champions prevent this advance. Astral Adepts are chosen from the Material plane either by bloodline or reputation to learn and grow. One day, they will finish their training and join the ranks in the Astral Plane in the eternal effort to hold back the advances of darkness on the universe.

Augmented Soul

When you choose this archetype at 3rd level, you learn how to augment your soul to access combat techniques drawn from the Astral Plane. The augments are managed through Astral Dice

Astral Dice. You have a number of astral dice equal to half your fighter level rounded down (minimum of 1), which are d6s. An astral die is expended when you use it. You regain half of your expended astral dice rounded down (minimum of 1) when you finish a short rest and all of your astral dice when you finish a long rest. At 10th level, your astral dice become d8s, and at 18th level, your astral dice become d10s.

Saving Throws. Some of your soul augments require your target to make a saving throw to resist the augment's effects. The saving throw DC is calculated as follows:

Augment save DC = 8 + your proficiency bonus + your Intelligence modifier

Elemency

At 3rd level, you learn the Elemency soul augment. When you are hit with acid, cold, fire, lightning, or thunder damage, you can expend one astral die to lessen its effect on you and store energy for your next melee attack. You have resistance to the triggering damage type until the start of your next turn. Also, the first time you hit with a melee attack on your next turn, the target takes an extra astral die damage of the triggering type.

Armiger

At 3rd level, you start to deepen your connection with the Astral Plane. You're able to store your weapons in a pocket in the Astral Plane and can use a bonus action to summon or swap weapons. All your weapons are now considered magical. Additionally, you can tap into martial prowess granted through your spiritual connection or lineage. You can select a new weapon for your armory given to you by Astral Champions of the past. When choosing a new weapon, you learn its associated fighting style.

You can choose a new astral weapon for your arsenal at 7th, 10th, and 15th levels. You cannot choose a weapon associated with a fighting style you already know.

Astral Longbow

You gain a +2 bonus to attack rolls you make with ranged weapons.

Astral Maul

When you roll a 1 or 2 on a damage die for an attack you make with a melee weapon that you are wielding with two hands, you can reroll the die and must use the new roll, even if the new roll is a 1 or a 2. The weapon must have the two-handed or versatile property for you to gain this benefit.

Astral Rapier

When you are wielding a melee weapon in one hand and no other weapons, you gain a +2 bonus to damage rolls with that weapon.

Astral Scimitars

When you engage in two-weapon fighting, you can add your ability modifier to the damage of the second attack.

Astral Tower Shield

When a creature you can see attacks a target other than you that is within 5 feet of you, you can use your reaction to impose disadvantage on the attack roll. You must be wielding a shield.

Silver Step

At 7th level, you can spend one astral die to take the Dodge action as a bonus action on your turn.

At 15th level, you learn the Astral Copy soul augment. When a creature misses you after you've taken the dodge action, you can spend an additional astral die to leave an astral copy of yourself behind. The creature must make a Wisdom (Perception) check to see through the illusion. On a success, nothing happens. On a fail, you have advantage on your next melee strike against that creature.

Improved Augmented Soul

At 10th level, your astral dice turn into d8s. At 18th level, they turn into d10s.

Astral Strike

At 10th level, you learn the Astral Strike soul augment. Expend one astral die and throw your weapon at a creature within 30 ft. and make an attack roll. On a miss, the weapon disappears into the Astral Plane and reappears in your hand at the end of your turn. On a hit, you teleport to your target and deal normal weapon damage plus your astral die's damage. 

Soul Link

At 15th level, you learn the Soul Link soul augment. When an ally deals damage to a creature you can within 60 ft. of you, you can expend one astral die as a reaction to teleport within melee range of the target. The creature must make a Dexterity saving throw. On a fail, the target takes force damage equal to your astral die plus strength modifier. On a success, they take no damage. 

Perfected Augmented Soul

At 18th level, your astral dice turn into d10s.