When you reach 3rd level, you gain one Feat of your choice.

Starting at 3rd level you can use your bonus action to assume a fighting stance. Choose one Mastery, you gain that Mastery on a weapon or shield that you are wielding, even if that weapon or shield cannot normally have that mastery. You can use this mastery for one minute or until you use this feature again. If you have a Mastery that requires a bonus action, you can activate it as part of the bonus action used to activate this stance.

You can use this feature a number of times equal to your proficiency bonus, and you regain all expended uses of it when you finish a short or long rest.

When you reach 7th level you Master 2 additional weapons. 

When you reach 10th level, you gain one feat of your choice.

Starting at 15th level, you may choose 2 Masteries rather than one when you use your Stance feature.

When you reach 18th level, you gain one feat or Legendary Boon of your choice.