The Toxic

You struck a bargain with a being of pure Poison, decay and toxicity. With it s knowledge it can poison everything and everybody. 
It can bring death in the most painful or unseen way. It will guide and evolve you into a being of pure toxins and poison. Even making you body to a mere vessel of death. 
You are its pawn to poison the world and bring even the gods to an end.

Expanded Spell List

1st-level Toxic feature

The Undead lets you choose from an expanded list of spells when you learn a warlock spell. The following spells are added to the warlock spell list for you.

Undead Expanded Spells

Spell Level	Spells
1st	bane, detect poison and disease
2nd	blindness/deafness, acid arrow
3rd	stinking cloud, toxic splash (another Homebrew Spell)
4th	confusion, phantasmal killer
5th	contagion, cloudkill

Bringer of poison

1st-level Toxic feature

You manifest your patron’s controll over Poisons and diseases. As a bonus action, for you can controll poisons for   1 minute. You gain the following benefits while transformed:

• Once during each of your turns, you  can use your bonus action to amplify the poison that flows though your enemies. each up to three creatures that are poisoned take 1d12 poison damage. This damage increases by 1d12 at 6th(2d12), 10th(3d12), and 14th(4d12) level.
• Once during each of your turns, when you were hit by a creature with an attack roll, you can use your reaction to force a creature to make a constitution saving throw against your spell save DC, and if the saving throw fails, the target is poisoned until for a Minute.
• You are immune to the poisoned condition and have resistance against poison damage

You can use this feature equal to your proficiency bonus, and you regain all expended uses when you finish a long rest.

The appearance of you changes acording to your  patron. For example, your can get snake Eyes, or your body might glow sickly green.

Poisoned blood

6th-level Toxic feature

Your Blood is now permantly considered as a poison. 

In addition, when a poisoned creature dies in next to you or is already dead you can absorb the poison in their blood, which grants you 1d12 +your Constitution modifier (minimum of 1 hit point) back.
While in manifestation mode you can also use this poison to poison another Enemy 30ft away from you instead of healing, dealing 1d12  and forcing the creature to take an Constituiton Saving Throw against your spell save DC, and if the saving throw fails the target is poisoned for a minute or you can deal 2d12 poison damage if the creature was already poisoned.

Once you use this feature, you can’t use it again until you finish a long rest.

You also can create, once a day, an antidote against your poisons making creatures who take it permantly immune to poison damage and being poisoned from you.

Perfected Poisoned Body

10th-level Toxic feature

Your connection to your patron grants you a perfected poisoned Body. All your attacks ignore Poison resistance and immunities and all your bodily fluids are now considerd a poison

In addition, you are granted a poisoned breath attack. as an action you can deal 3d12 poison damage and poisoning everybody in a 20ft line infornt of you . 

You can use this Feature equal toyour profiency  bonus. Regaining all uses when you Long Rest.

Master of poisons.

14th-level Toxic feature

You are permantly surounded by an invisible gaseos poison that u can activate as an action to poison everybody in a 10ft sphere around you for up to 30 Minutes.

You Mastery and Knowledge given by your Patron grants you the ability to create the perfect poison. 
When you roll Poison damage you can treat the roll as maximum damage.
you can use this feature equal to your charisma modifier and regain all uses on a long rest.