Many clerics of the Transgression Domain (colloquially known as the Sin Domain) have abandoned their former faith/god(s) and the constant struggle to lead a virtuous life to embrace the worldly gratifications of sin. Deities of "sin" such as Asmodeus, Loviatar (the Maiden of Pain), Sharess (The Dancing Lady), or Abbathor, the dwarven god of greed tempt their followers with promises of pleasure or power beyond their wildest dreams. Some mortals simply worship fiendish entities such as Graz'zt, Lady Fierna, or Malcanthet the Queen of Succubi, convinced that transgressing the moral laws of the "holy" gods is the most honest and rewarding path for mortal creatures. "Only by surrendering to temptation can we in truth overcome it."

Shun by the faithful of "virtuous" gods, clerics of the transgression domain often masquerade as clerics of respected domains, worshiping their true gods behind closed doors, in the shadows, or shady neighborhoods of large cities. 

Although they give in to all matters of vice, each cleric has his or her favorite transgression. A fallen cleric can be of any alignment, but it gains one of the following flaws (player's choice).

• Envy.  “The material world as so much to offer. I want it all, especially if someone else already has it..."
• Gluttony. “I can’t stop thinking about drink and food. Point me to the nearest tavern or festhall."
• Greed. “I’m obsessed with wealth and material things. I just can’t get enough.”
• Lust. “I can’t control my lustful thoughts and desires. Pleasure is my treasure."
• Pride. “I am superior and, of course, always right. Bow down to my magnificence.”
• Sloth. "All I want to do is rest. I've got nothing to prove and nowhere to go."
• Wrath. “I am impatient, prone to bursts of violence. My fiery temper makes me feared and respected."

Atonement

With the DM's permission, fallen clerics can atone for their transgressions through words and deeds and revert as clerics of a former or alternate domain (losing all features of this domain and gaining the other ones).

Transgression Domain Spells

Transgression Domain spells mirror some of the common vices: envy, gluttony, greed, lust, pride, sloth, and wrath.

 * contact other plane: the entity you contact is a mysterious fiend from the Abyss or the Nine-Hells, which unbeknown to you, has been tempting you for many years. 

Transgression Domain Spells

Silver-Tongued

The graces granted by your charismatic deity makes you particularly adept at manipulating the common folk. You become proficient in the Deception skill, and you have advantage on Charisma (Persuasion) and Charisma (Deception) checks made when interacting with nonhostile humanoids and giants. 

Channel Divinity: Animal Instinct

Your wild and fiendish abandonment to sinful ways have earned you the power of therianthropy. 

Starting at 2nd level, as an action, you can use your Channel Divinity to assume the shape of one of the following animals. The animals are associated with a particular vice, but you can assume the shape of any of these beasts: frog or giant frog (greed), poisonous snake or giant poisonous snake (envy), boar (gluttony), goat (lust), elk or wolf (pride), cat or squirrel (use rat statistics with a climbing speed of 20 feet) (sloth), or lion (wrath). 

You must concentrate while using this feature, and any worn or carried equipment melds into your new form. You gain a number of temporary hit points equal to the hit points of your new form. These temporary hit points can’t be replaced by temporary hit points from another source. While in your animal form, you retain your mental stats (Intelligence, Wisdom, Charisma). You can remain in this form for up to 10 minutes. You revert to your normal form if you have no more temporary hit points, if you lose concentration or fall unconscious, or if you die. You can also end the effect early and revert to your normal form by using a bonus action.

After you reach 5th level, you can remain in your animal form for up to 1 hour, and you can assume the form of an bat (sloth), eagle (pride), giant goat (lust), or flying snake (lust).

Channel Divinity: Touch of Sin

Starting at 6th level, you can use your Channel Divinity to cause bliss, joy, or pain. 

As an action, you touch a creature within 5 feet of you. The target is overcome with pleasure or laughter, or wracked with physical pain (your choice) for 1 minute. It must succeed on a Wisdom saving throw of fall prone, becoming incapacitated and unable to stand up for the duration. At the end of each of its turns and each time it takes damage, the target can make another Wisdom saving throw. The target has advantage on the saving throw if it's triggered by damage. On a success the effect ends.

Divine Strike

At 8th level, you gain the ability to infuse your weapon strikes with necrotic energy. Once on each of the cleric’s turns when you hit a creature with a weapon attack, you can cause the attack to deal an extra 1d8 necrotic damage to the target. When you reach 14th level, the extra damage increases to 2d8.

Master of Temptation

Starting at 17th level, when you cast a necromancy or an enchantment spell of 1st through 3rd level that targets only one creature, you can instead target two creatures within range and within 5 feet of each other. If the spell consumes its material components, you must provide them for each target.