Revenant subclass

You have already died but you will not fall, revenants are humans that got revived by a man made parasite 

they utilize the power of the queen a magical being of immense power to fight endlessly in battle 

they cannot, die they refuse to do so

Revenants’ Concoctions

You learn how to utilize your alchemical prowess to maintain your body with alchemical processes 

Starting at 3rd level, You gain Proficiency with Alchemist's Supplies and Brewer’s Supplies

Blood veil

 You gain the ability to summon weapons out of your own blood.

Starting at level 3, You gain the ability to use your blood and summon any martial weapon you may only have one at a time but can switch between them as a action

At level 7, it becomes a +1 martial weapon and again at level 10 it becomes a +2 martial weapon and finally at level 15 a +3 martial weapon

Revenant’s Nimbleness

as all revenants are agile so are you you gain the ability to dodge atacks when you focus and furthermore even as a reaction

Starting at 7rd level, You gain the ability use the Dodge Action as a Bonus Action 

At level 10 you gain the ability to use the Dodge as a reaction twice  per Long Res

Rejuvenation

you gain the ability to rejuvenate health on battle via blood

starting at level 10 you can after dealing damage to a enemy you can choose to regain 5+CON+fighter level hitpoints as a free action

you can only use it twice per long rest

Awakening

you can awaken your full blood code for a short period of time 

Starting at level 15 You gain the ability to awaken yourself as an action, 

You gain 1d10+STR+fighter level of temp hitpoints and you also gain plus 1d4+STR to all melee hits for one hour and on critical hits you activate rejuvenation without spending one of its slots 

You can use it once per long rest

The queen's paradox

You are a true revenant you have learned how to use the full power of your blood and maybe even surpass the queen herself?

Starting at level 18, You gain the ability to remain alive even after  you fail 3 death saving throws, you will lose control over yourself and attack randomly for 2 rounds. You become dormant after said incident until revived by a party member. If you receive healing while in this state you fall prone and unconscious until you receive healing a second time after that. Keep in mind you could still activate your ability to rejuvenate to knock yourself unconscious however doing that will consume both uses of that ability and cause you to gain one point of Exhaustion.