Final Heroic Stand

Backstory: There are story's of hero's fighting until the end, even though there body's have given up. people say its just an adrenaline rush but others say that its more, Its more like there body's pushing past death and becoming a true hero 

Final Stand: Whenever the person with this feat hit to 0 HP but not killed outright. the hero may use there reaction to active the feat.

Beating All Odds: Instead of falling unconscious, your heart convulses and forces your dead body to keep fighting.

You immediately gain temporary HP equal to half of your maximum HP.
You remain conscious and able to act, even though your body is technically dead.
While in this state:
-You are immune to being charmed.
-You are immune to being poisoned.

You are fighting on pure willpower and a heart beating far beyond safe limits.

The Bloody Beat: Due to the blood pouring out of there eyes, ears, mouth and nose. not everything is going good due to
-Technically Dead: Due to your body pushing throw death and keep moving, you are unable to be heal by normal means ( like healing word and cure wounds ).
-Bloody Eyes: Due to the blood filling there eyes. They can only see though a red haze causing the hero to make attack rolls with disadvantage, also making Perception checks with disadvantage
-Bloody Ears: Due to the blood filling there ears. The hero comes deafened as the blood fills the ear cannel
-Bloody Mouth: Due to the blood filling there Throat and Mouth. The hero is unable to speak, this effects anything that needs a verbal to use it

The Final Blow: If the hero falls while still in battle, they fall dead as they are able to be bring back by normal means. If the hero is still standing at the end of the fight, they must roll a d20 at the end of there next turn. The DC equal to the table below  

-Around Half Of There HP: They must roll more than 10 
-Under A Quarter Of There HP: They must roll more than 15 
-Until 10 HP: They must roll a nat 20

The Consequences Of Your Actions: If the hero succusses on the roll, there heart is able to stabilise itself. Coming to a stop as you fall dead, The hero is able to be brought back by normal means. If the hero fails the roll, there heart is unable to stabilise itself and explodes aggressively causing severe damage to there organs. they fall dead and is unable to be bought back by normal mean ( like Revivify )

The Lasting Damage: If the hero falls and still has a heart. they are unable to use this ability again for a week as it puts too much strain on the heart that you need to let it clam down. if the character has to be bring back with a new heart. they gain the ability back after a long rest