Either in the thralls of combat or the vastness of training you have acquired the ability to change your fighting style at a moments notice. With the ability to adapt to the coming challenges your a danger to anyone who opposes you.

• As a bonus action you can change your fighting style to adapt to what best suits you. 
• If multiple types are known up to two can be changed with a single bonus action. Though no duplicate styles can be selected. For example you can’t have two defense types.