The Abyssal Entropist is a wizard, who can gains powerful boons through their Abyssal Artifact. Activating one of these boons does come at a price. And if an Abyssal Entropist breaks the rule of their artifact, then horrid consequences await.

Natus Tenebrae

Choose an appearance for your relic. It can range from a shard of a dark crystal to a replaced abyssal bodypart.

So now choose the boon your abyssal relic grants you:

• Nocturnal Spellbinder - As a reaction, when a creature up to 30ft away from you casts a spell, you can sap energy from it, increasing the DC of the next spell you cast by the level of the spell you sapped the energy from.
• Black Rupture - When one of your spells damage a creature, you can have it take 1d4xYourWizardLevel Force damage as dark energy ruptures out of the creature. (up to 8d4)
• Shield of Night - As a bonus action, you can gain 1d4xYourWizardLevel temporary hitpoints until your next turn.
• Visions from the Void - A creature up to 30ft away from you gains disadvantage on any roll against you for 1 minute. It can make a DC(8+Your profficiency Bonus + Your intelligence modifier) Wisdom saving throw at the end of its turn to end the effect prematurely.

Then choose the price you have to pay to activate your boon:

• Blood - Sacrifice Max 2d4hp. The amount of dice increses by 2d4 after every activation of your boon. This resets on a short rest and you regain the lost HP on a long rest.
• Mind - Loose 1d4 Intelligence. The lost intelligence regenerates after a long rest.
• Fate - The next roll you make is made with disadvantage. You can only activate your boon again after making a roll.
•  Memory - Forget a prepared spell.

Now choose the rule you have to follow to keep the power over your artifact:

• Night - The Day is a curse, the artifact may not come into contact with sunlight.
• Sacrifice - The artifact hungers, you must sacrifice one living being which is at least the size of a dog, every day ,through a ritual which takes up 1 hour.
• Peace - The artifact dislikes death. You may harm living beings, but not directly kill them. 
• Indulgence - You must always give into your emotions and may never ignore a craving.

And finally, choose the consequence when you break the rule:

• Berserk - You loose conciousness, as the hungering void of the artifact goes berserk for 12 hours, forming a huge creature around your body. This monstrosity will try to kill everything it sees, preferring anyone you hold close. If the creature is slain you fall out of its dissolving body and stay unconscious for 2d4 hours.                                                      The creature is an Abyssal Horror. 
• Mindburn - Your Intelligence drops to 1 for 2d4 Days. This cant be mitigated by magical items or effect. Every time this consequence activates the time your Intelligence is 1 doubles.
• Traitor - A friend of yours will be possessed by a dark spirit. They will randomly decide to kill you, only their own death or a wish spell changing their mind.
• Weakling - Loose the ability to cast spells for 2d4 Days. Every time this consequence activates the time you cant cast spells doubles.

Confortatus

During a long rest, you can enhance one of your spells through a ritual with your artifact. Choose a positive effect of the enhancement:

• Ares - You may reroll 2 dice from the spells damage and must use the new rolls.
• Dionysus - When casting the spell, gain temporary hitpoints equal to its level. 
• Zeus - When casting the spell, choose a creature up to 30ft away from you, it takes 1d8 Necrotic and 1d8 lightning damage if it fails a DEX saving throw with a DC equal to your spell DC, as dark lightning strikes it.
• Poseidon - You can push up to 2 creatures affected by your spell up to 10ft in any direction you choose.  
• Artemis - The range OR radius OR width of your spell is increased by 5ft.
• Orpheus - Your spell doesnt require V,S or M components and is invisible to anyone but you and creatures affected by it. True sight ignores this invisibility.

But casting the spell also poses a challenge. Choose a negative effect of the enhancement:

• Apicem - You cant cast the spell at a higher level.
• Luna - You can only cast the spell at night.
• Sol - You can only cast the spell at day.
• Immoderata - Your spell has a 25% chance to affect a Target chosen by the GM instead.

Aurora Fracture

As an action, you may unleash a storm of necrotic and radiant energy centered on yourself by using yourself as a catalyst for your artifacts power. The storm is a sphere with a 25ft Radius and deals 6d6 Necrotic and 6d6 Radiant damage to anyone caught in it if they fail a +WIS saving throw. Otherwise they only take 3/4 of the damage. You fail the saving throw automatically, but the storm will not drop you below 1 hitpoint. You may use this feature once and regain the use of it on a long rest.

Suscitans

You may cast spells with a casting of 1 action as a bonus action and increase its DC by 1d4+1. If you choose to use this option you will be also affected by the spell (if it does something negative to the affected) or affect an enemy (if it does something positive to the affected) of the GMs choice. Even if you or the enemy isnt in range of said spell.