Braking strike

You’ve train yourself with the skills and strength to hold your own in close-quarters fighting. And after a deep primordial scream you gain the following benefits:

• You have advantage on attack and damage rolls against a creature you are attacking.
• You can use your action to strike with incredible force ignoring your natural survival instincts.
• On two successful hits in a row the AC of the creature you hit is reduced by 2
• Once this Feat is activated it continues until the creature you first hits dies or if you die or after 5 hours without combat. 
• Each attack is far grater than what your body can handle at this time, you fight though the pain with each strike. On each attack, triple the dice used. However you take 20% of the total damage on each successful strike. 

• Additional effect: Due to the Pain you are immune to be frightened. Advantage on grappling with an extra +3 to the roll. Resistant to cold damage and when attacked gains a reaction to retaliate and attack, up to 3 times in 1 round of combat.