Long-term exposure to performance-enhancing drugs changed your physiology. Accustomed to sudden adrenaline rushes, your body gained the ability to process time differently. At the beginning of any of your turns you can activate your ADD (no action required by you). Your body jumps into overdrive and while in it, you gain the following benefits:

• you can make one additional attack when you take the Attack action
• you can take Dash action as a bonus action
• your AC is increased by 1 each round while overdrive is activated

While in overdrive, your mind struggles to process information at a higher rate. To maintain the overdrive, you must concentrate (as if you were concentrating on a spell). Additionally, while overdrive is activated, at the end of each of your turns you must succeed on a Wisdom saving throw. The DC starts at 10 and increases by 5 for each round you spend in overdrive. If you fail that saving throw, you are stunned for one minute. You can repeat the saving throw at the end of each of your subsequent turns to end stunned condition. The DC is reset when you take a short rest. 

You can exit overdrive state at the beginning of each of your turns (no action required by you).