At first, it will seem difficult, but everything is difficult at first. Drawing a bow is hard, wielding a halberd is challenging; but as you practice, your strength will grow. In time, as you become accustomed to the bow, your pull will grow stronger. Similarly, as you master the sword, you will come to understand the Way, and your skill with the blade will flourish.

Level 3: Wisdom of Water

At 3rd level, both in combat and in everyday life, you should strive to be determined yet calm. Face each situation without tension, but also without recklessness — your spirit should be settled, yet unbiased. When you take the Attack action  on your turn, you may use this feature once to replace one of your melee weapon attacks with one of the following abilities.

Cutting the Waters Surface.

You can draw and slash with the weapon in a circular motion. All creatures within 5 feet of you must make a dexterity saving throw. On a failed save, creatures take slashing damage equal to a roll of your weapon die.

At level 15 Cutting the Waters Surface feature deals an additional weapon die of damage and disperses gases and vapors in the area when used.

Edge of the Waters Reflection

You attempt to parry with a weapon. You gain a +2 bonus to AC until the start of your next turn, until you are incapacitated, or until you stop wielding the weapon. If a creature misses a a weapon attack against you while you are parrying you can use your reaction to make a melee weapon attack against that creature. On hit you deal additional damage equal to half your fighter level.

Disciple of Strategy and Steel

At 3rd level, In strategy it is necessary to treat training as part of normal life with your spirit unchanging. You gain proficiency with a Gaming Set of your choice and longswords count as finesse weapons for you. When a feature in this class calls for a saving throw use the below formula.

Sword Save DC = 8 + your proficiency bonus + your Dexterity modifier

Wisdom of Fire

At 7th level, in large-scale strategy, when you cannot see the enemy’s position, signal that you are preparing a strong attack. This will force your opponent to reveal their resources or tactics. Once you have discovered their weaknesses, you can easily adjust your strategy to defeat them in a different way.

Burning March. If you reduce a creature to 0 hit points you can move up to half your movement speed toward another creature. The next attack roll you make on this turn is made at advantage.

Wisdom of Earth

At 10th level, you possess an understanding of both the smallest details and the grandest concepts, the shallowest matters and the deepest truths — as if they were clearly marked on a straight path before you.

Eyes of the Mountain. You have a tremorsense out to a 20 foot radius. At level 18 this increases to 40ft

Wisdom of Wind

At 15th level, the true meaning of swordsmanship no longer lies in specific stances or techniques. Instead, you must keep your spirit unwavering and true, for it is this clarity that reveals the true virtue of strategy.

Bottling the Storm. Your walking speed increases by 10 feet and attacks of opportunity are made against you at disadvantage.

Wisdom of Void

At 18th level, the concept of ‘void’ represents something without beginning or end. To truly understand this principle is, in itself, to not fully grasp it. The Way of strategy is the Way of nature. By aligning yourself with the rhythms of nature and understanding the flow of any situation, you will strike your enemy effortlessly and naturally.

Nirvana. You still your very essence and adopt a stance attuned to the space around you. As a bonus action you can adopt the Void stance, when you do you may choose one of the following affects. You can use this feature only if you haven't moved during this turn, and after you use it, your Speed is 0 until the end of the current turn.

Presence of Nothingness

When you adopt the void stance your sword bends through the void, the very space around you becoming your blade, your weapon is considered to have a reach of 30ft, allowing you to attack any creature you can see with any sense you have until the end of your current turn. You are also considered to be within 5ft of any creature within that 30ft and can use any ability that requires you to be within certain range of creatures.

Stillness of the Void

When you adopt void stance you can become the very void itself, you gain resistance to all damage except psychic until the start of your next turn.