Gosu Warrior

A warrior stands on the battlefield alone, surrounded by a hand's worth of soldiers. Wearing his mighty heavy armour and carrying his bloodied halberd, he stares defiantly at his angry and bloodthirsty opponents. As one rushes in to strike him, he steps aside, his foot causing the fool to slip and fall, and his halberd's blade buries itself into his chest as he lands. Another two move in swiftly, brandishing spears to impale the man, but as they get close, the fearsome blade separates one's soul from his body, and with a swift punch to the throat, the other collapses, breathless. The great warrior charges, sweeping his polearm across the ground before leaping, slamming it into the neck of one more foe, before driving the butt of his blade into the breathless one. He briefly stands up, straight-backed, facing the final warrior. He bends over forward, bowing respectfully, before raising his weapon with a sweeping flourish, ready for a good fight.

Disciplined Arts

At 3rd level, your discipline and practice give you mastery of combat styles that use martial weapons, force, and agility.

You gain the following benefits when wielding only a martial melee weapon, a spear, or a mace, and you aren’t wielding a shield:

• When you use the Attack action with a weapon on your turn, you can make one unarmed strike as a bonus action.
• You can roll a d4 in place of the normal damage of your unarmed strike. This die changes as you gain levels in this class, as shown in the Disciplined Arts column. This increases to a d6 at level 9, and a d8 at level 15.
• You can choose to use Dexterity instead of Strength for the attack and damage rolls of your unarmed strikes.

Refinement

At 7th Level, the intensity of your determination sets you apart from other fighters. Your second wind and action surge features become more potent.

Your second wind feature gains the following benefits:

• If you are prone, activating second wind allows you to stand as part of the bonus action, using none of your movement.
• If an effect would leave you stunned, you can use your reaction to activate second wind, negating it in addition to its normal benefits.

Your action surge feature gains the following benefit:

• When activating action surge, you can use the dash action as a bonus action until the end of your turn.

Deflection

At 10th level, you can use your reaction to deflect or catch a weapon attack. When you do so, the damage you take from the attack is reduced by 1d8 + your fighter level.

If you reduce the damage to 0, you can make an attack as part of the same reaction.

• If the attack was with a melee weapon, you can make an unarmed strike.
• If the attack was with a ranged weapon and the missile is small enough for you to hold in one hand, you can catch it. You can then choose to make a ranged attack with a range of 20/60 using the weapon or piece of ammunition you just caught. You make this attack with proficiency, regardless of your weapon proficiencies.

You can use this attack a number of times equal to your strength or dexterity modifier (your choice, minimum of once), and only once per round.

Rapid Reflexes

At 15th level, your keen senses and focused movements allow you to react with incredible speed, and you are even able to react to multiple threats. Once per turn, if you’ve already taken your reaction, you may give yourself an additional reaction. 

You can use this feature a number of times equal to your Wisdom modifier (a minimum of once). You regain all expended uses when you finish a long rest.

In addition, you can't be surprised while conscious.

Musou Perfection

Starting at 18th level, combat energizes you and pushes you beyond the limits of all but the most dedicated warriors. Whenever you roll initiative, you can use your reaction to activate a haste-like effect; you double your speed, you gain a +2 bonus to AC, you have advantage on Dexterity saving throws, and you gain an additional action on each of your turns. That action can be used only to take the Attack (one weapon attack only), Dash, Disengage, Hide, or Use an Object action. You also have advantage on the initiative roll that triggered this. This lasts for a minute, until you are knocked incapacitated, or you die. 

You can't use this feature again until you finish a short rest.