Hysterical Power

In moments of life and death you can tap into the absolute peak of your abilities and push your body to its limit. 

While in combat and you are bloodied (below half health) you may choose to use this feat when you hit with an attack or cast a spell. When you use this feat you take  damage Xd4 damage where X is your character level this damage cannot be prevented or reduced, in addition your max health drops by the same amount until you complete a long rest. You can only use this feat once per turn.

Whenever you hit a melee attack, the attack is treated as a critical hit and the weapon dice are maxed. Any other benefit or feature that allows you to add additional damage dice such as Smite, Battle Maneuvers or Bardic Inspiration, roll those dice as normal.

Whenever casting a spell that requires a ranged spell attack you have advantage and treat any hit as a crit. 

Whenever casting a spell that requires a save all effected creatures have disadvantage on all saves against the spell and all damage on the turn it was cast is maxed.