Flash Step

Increase your Dexterity or Strength score by 1, to a maximum of 20. 

You channel your speed, allowing you to become almost invisible for a moment. You can use your movement (minimum of 10ft must be used in a straight line) and choose a target and close the distance to them. If you move in this way, you may roll a stealth check against their perception (active). If you succeed, your next attack against the target is at advantage. If you fail, the target notices you, they can use their reaction to make an attack of opportunity against you at disadvantage. Visual abilities do not effect this ability, as even the most perceptive need speed to react accordingly. This ability does not provoke attacks of opportunity when moving outside of an opponents range.

Your speed extends now to your reflexes, allowing you to potentially step away from danger. When you make a dexterity saving throw against a hostile or environmental effect, you may choose a creature within range of your movement. You move to that target. This may cause the original triggering ability to no longer effect you due to range and area. Until the end of your next turn your speed is 0 and you cannot move.