You can make two attacks instead of one when you take the Attack action on your turn.

As a Bonus Action, enter a rage for up to 10 minutes if not wearing Heavy armor. While raging, gain resistance to Bludgeoning, Piercing, and Slashing damage, deal extra damage with Strength-based attacks, and have Advantage on Strength checks and saving throws. Rage ends early if incapacitated or if you neither attack nor force a saving throw during a turn.

Your Rage lasts until the end of your next turn if you do not attack, force a saving throw, or take a Bonus Action to extend it. It also ends early only if you become Unconscious or choose to end it.

When a creature within 60 feet fails a saving throw while frightened, you can use your Reaction to force it to repeat the saving throw, potentially turning the failure into a success.

While not wearing armor, your Armor Class equals 10 + your Dexterity modifier + your Constitution modifier. You can use a shield and still gain this benefit.

You can use the Mastery property of two kinds of Simple or Martial weapons. You can change one selected weapon whenever you finish a Long Rest.

You have Advantage on Dexterity saving throws unless you are Incapacitated.

You gain Advantage on attack rolls using Strength during your turn, but attack rolls against you have Advantage until your next turn.

Your Speed increases by 10 feet while you are not wearing Heavy armor.

You have Advantage on Initiative rolls. If you are surprised at the start of combat, you can act normally if you enter your Rage before doing anything else.

Once per turn, when you make an attack using Strength that deals damage, you can replace one extra Rage damage die with a Brutal Strike. The attack deals extra damage and you can apply one listed additional effect, such as Forceful Blow or Hamstring Blow.

If you drop to 0 Hit Points while raging and do not die outright, you can make a DC 10 Constitution saving throw. On a success, you drop to 1 Hit Point instead. The DC increases by 5 after each use and resets after a Short or Long Rest.

When you use Brutal Strike, you can use two different Brutal Strike effects instead of one, and the extra damage increases.

Your Strength and Constitution scores increase by 4, to a maximum of 25. These increases are reflected in the ability scores above.

You gain an Epic Boon feat. Mizuno has taken Boon of Irresistible Offense, allowing his attacks to ignore resistance to Bludgeoning, Piercing, and Slashing damage and deal extra damage when he rolls a 20 on a weapon attack.

While raging, you can use Frenzy when you deal damage with a Reckless Attack. Once per turn, the attack deals extra damage equal to one Rage damage die. The extra damage can be dealt only once per turn.

When you enter your Rage, you can frighten creatures of your choice within 30 feet that fail a Wisdom saving throw. The effect lasts until the end of your next turn, and a frightened creature can repeat the save at the end of each of its turns.

When you enter your Rage, you can gain temporary Hit Points equal to your Barbarian level. While raging, when a creature within 30 feet drops to 0 Hit Points, you can gain temporary Hit Points again without using an action.

Mizuno retains the respect and practical privileges of his former military rank. Soldiers who recognize his service may offer shelter, information, or limited assistance, though they will not obey suicidal or obviously unlawful orders.