A Fighter's spirit is the will that moves them through the tides of battle. Those of particularly powerful will can manifest their souls in the form of a weapon bonded to them completely. A Soul Blade is an example of this will made real, and those that can manifest such a weapon gain the power to wade through the fields of battle, blade held aloft as a standard of your bravery.

Soul Manifestation

The power of your soul allows you to manifest a blade made solely of your own willpower. When you choose this class at 3rd level, choose a martial or ranged weapon. As a bonus action, you may summon a weapon of the chosen type in your hand, referred to in this archetype as a Soul Blade. Your Soul Blade counts as magical for the purpose of overcoming Resistance and immunity to nonmagical attacks and damage.

You can transform one Magic Weapon into your soul blade by performing a Special ritual while you hold the weapon as long as it is of the same weapon category, melee or ranged, as your Soul Blade. At the end of the ritual, the weapon transforms into the form of the weapon you chose when you first chose this class. You perform the ritual over the course of 1 hour, which can be done during a Short Rest. The weapon ceases being your Soul Blade if you die, if you perform the 1-hour ritual on a different weapon, or if you use a 1-hour ritual to break your bond to it. The weapon is destroyed when the bond breaks. This ability may not function at the DMs discretion if the enchantment of the weapon relies on a specific property of the weapon not shared by your Soul Blade, eg. a feature that is dependent on a reach weapon when your Soul Blade is a longsword.

Flurry Strike At 3rd level your Soul Blade can learn about enemies by repeatedly striking their essence. When you hit a creature with an attack with your Soul Blade, you deal an additional 1 point of damage for each successful consecutive attack you've made against that creature. This damage bonus is reset to 0 if you miss an attack against the creature, attack a different creature, or take any action other than the Attack action. If this bonus to damage reaches 5 points, you gain permanent advantage on all attack rolls you make against that creature with your Soul Blade regardless of the previous conditions that would reset the bonus.