Although typically explored in a more religious context, the Seven Deadly Sins do not have to be inherently religious in depiction or characterization. However, because they are most commonly depicted as demons and devils, they fit right in withDungeons & Dragonsand its copious amount of devilish adversaries.
Whether you’re descending into Avernus or you’re simply trying to build a campaign where the players are set to save the world, the Seven Deadly Sins can prove to be unique adversaries or - in the odd case - perhaps even allies. You will need to homebrew (a lot), but encounters with deadly sins will no doubt prove to be memorable.

8Get A List Of Player Character Sins
Really Make Your Players Think
If you plan to introduce any Deadly Sins into your campaign, you should take the time to gather some information from each of your players. Make them take the time to think long and hard about their characters and just what their character’s Deadly Sin might be.
From there, you can incorporate that Deadly Sin into your campaign, and really take the time to pit your players up against their own issues to encourage character development. Plus, if you include the embodiment of that sin, perhaps that Deadly Sin will hold more power or sway over that specific player.

7Not Everything Needs To Be A Fight
Consider A Test Of Will, Instead
If you opt to include the embodiments of the Seven Deadly Sins in your campaign, or you decide to explore the different Deadly Sins, you don’t need to set it all up to be a fight. Sure, fights can be rewarding for some players, but it’s not the be-all-end-all of Dungeons & Dragons.
Instead, consider doing a layered Dungeon, where each level represents a different Deadly Sin, andhave your players go through a somewhat classic dungeon crawl. To beat the level, they need to confront the sin head-on with its opposing virtue - Gluttony is counteracted with resisting indulgence, Greed is counteracted by selflessness, and so on.

6Sins Are Not One-Note Endeavors
Consider Giving Them Added Nuance
As time continues to march forward, different situations become less one-noted and gain additional nuance. Greed may not mean just the desire to have excess wealth, but it can also encompass the desire to hoard things away without reverence for the world around you. Lust doesn’t necessarily have to pertain to intimacy, but it can instead embody the endless drive for power, no matter how dangerous or harmful that search for power may be.
Gluttony is an overindulgence that isn’t just restricted to food, but could instead be applied to addictions. Providing your players with a nuanced view of the Deadly Sins can create really unique encounters and encourage them to think creatively about how to handle different problems.

5Physical Embodiments Affecting The World
Just Standing There, Ominously
If you decide to introduce the Deadly Sins in a physical form, consider how that form would affect the world or make NPCs with lower constitutions or wisdom more likely to indulge in the corresponding sin.
It’s a really great way to depict the visual impact of one of the Seven Deadly Sins existing within your world, and it helps to portray why they can be so dangerous. Rather than simply indulging in their own sin, their mere presence is actively encouraging and perpetuating their sin until,eventually, they end up with their own lairof vice and indulgence.

4Modified Stats
Build Off Another Foundation
Although your players probably shouldn’t fight a Deadly Sin, there’s nothing saying that they can’t (unless you, as the Dungeon Master, are drawing a line and saying that they can’t). Either way, it’s good to have some stats on hand if you’re introducing a physical NPC they can interact with.
Rather than building everything from scratch, you should consider utilizing stats that already exist as a foundation to work off of and to modify, and for a deadly sin,you should probably pick from some of the more powerful devils and infernal creatures. For example, you could combine an Incubus and Succubus, with additional modifications to make them more dangerous for Lust. Perhaps a stronger Bone Devil could work for Wrath, in both aesthetics and stats.

3Intermingling Abilities
Sins Are Not Completely Separate
If you opt to make special abilities for your Deadly Sins that influence the world, or if you are simply portraying that influence, keep in mind that sins are not completely separate from each other. A wounded pride can easily bleed over into a more wrathful vengeance for that wound.
Gluttony can easily go hand in hand with greed, as you overindulge and refuse to share in that indulgence. Lust for someone’s things or someone’s partner can easily bleed into intense envy, and, over time, even into something more dangerous and wrathful. Feel free to combine the deadly sins to empower them or make them more dangerous when grouped together.

2Fluctuating Power
The More Vice And Indulgence, The More Power
If you decide to introduce a physical embodiment of a Deadly Sin into your world, then consider how their power levels would fluctuate depending on where they are. While their abilities might feed into the encouragement of sin and vice, the more sin and vice there is, the more likely they are to be emboldened and more powerful.
Just as their presence encourages sin, the excess of that sin should empower them. A Deadly Sin living in a town of vice would be more powerful than one living in a town of virtue, though the corruption of that virtue might make it a tantalizing target.

1Double-Edged Patrons
For Your Warlocks And Evil Paladins
If you happen to be running a campaign where players can maintain evil alignments, then there’s a chance that you might be able to make a patron for warlocks, paladins, clerics, or so on that’s a Deadly Sin. If you do so, consider that as a beneficiary of that sin, your player would be more likely to indulge in that sin while, perhaps, being less likely to fall prey to other vices.
While the encouragement of that sin could make them more powerful, indulging in it themselves could have negative side effects and strain their relationships, make it harder to accomplish their goals, or generally just make their lives a bit more difficult - nobody said being evil would be easy.
