Blessed by the Black Sparks

You gain preternatural precision in your strikes, causing black lightning to erupt from your critical blows and temporarily causing your body to enter a flow state. When you land a critical hit with an attack roll, you deal extra force damage equal to your proficiency bonus and gain the following benefits:

• Until the start of your next turn, you have advantage on attack rolls, and can reroll one of the attack roll dice once per attack.
• You gain temporary hit points equal to 2 × your proficiency bonus.

Black Spark Refresh. Additionally, when you land two critical hits in a single round, you can choose to immediately gain the benefits of a short rest. Once you gain the benefits of a short rest in this way, you cannot do so again until you complete a long rest.