path of the psycho (krieg from BL2)

Basically I like Krieg the Psycho a lot, and wanted to make a subclass for my boy.  I am going to be trying to be trying to putting his skills from mostly the bloodlust, and mania tree into dnd, mainly because Hellborn's skills I don't know how to put into dnd with out breaking some rules. I will try my best to make it not broken, since I do want to use this subclass, but If you do see this, and think something is over powered, or have a better idea for how a skill can be implemented, please comment. 

Empty the Rage

Starting at 3rd level when you rage your rage damage is replaced by a d6. Which increases to a d8 at level 10, and a d12 (or two d6 if you want, but tell your dm which you are going to use) at level 16. In addition each time you attack, roll a percental dice, (or a d100 if you have it), and if you roll a 88, or higher you deal the damage of the attack to your self. 

Redeem the Soul

At level 6 you can sacrifice your health to heal someone from the dying state as a bonus action (range melee), they gain health equal to the amount sacrificed, if you go down from this you have advantage on death saving throughs.  

Release the Beast

At level 10 when you are at 33% of your max health or less, and activate your rage you grow one size category(If you don't have room to grow all instead only your arms grow.) (Side note everything grows with you), you add your str mod to your rage damage, and minus all incoming damage by 3.

Bloodsplosion

At level 14 killing an enemy causes an elemental blast 10 feet in radius that only effects creatures you consider enemies, this blast deals the amount of damage equal to the amount of damage left over from killing the first enemy. Hostels need to make a 8+ your dex mod + proficiency, if they succeeded they take half damage. If an enemy dies from this damage they also causes an elemental blast, which it's damage is the overkill damage.