How do you play powerful characters or NPCs with a dark, tragic past?

A few days ago, I had this idea for an NPC.  She is a fantasy interpretation of Saint Lucia of Syracuse, that has been heavily influenced by the Dante's Inferno incarnation of her character.

Her backstory is dark and twisted, full of abusers and defilers. She has suffered, more than any mortal should ever have to suffer, and that suffering has turned her into a Paladin of Vengeance.

While discussing this NPC on Reddit, lots of people pointed out that she is an OP edgelord of cringe, and this got me thinking.

How do you play characters or NPC's who have horrible, dark, twisted backstories that make the other players shudder, without them becoming a lord of cringe?

Also, as a DM, how do you play extremely powerful NPCs, without them seeming OP, and should you even try?

So guys and girls and beyonders.  Copper for your thoughts!

One of the defining traits of cringe-y characters for the edgelord flavor is the fact that they are always brooding, looking people with disdain or contempt for their ignorance of how dark and horrible the world really is, and most often than not all too ready to tell everyone of their tragic past, how they suffered, how they are really-really angry all the time, how powerful they are due to their suffering etc.

Just... don't play them like that.
Someone who suffered a lot will most probably not be too fond of sharing their experiences with anyone they do not know and trust, especially if they are still hurting or have been too deeply changed by these experiences. Rather than being suspicious of everyone and everything and being angry all the time, they would most probably just try to avoid unnecessary contact with anyone, but it's not like they are completely antisocial and incapable of basic social interaction.
They would also most probably not consider themselves powerful, as people who suffered a lot usually feel small and weak, unless they somehow got over their suffering, therefore they would not do much unless inevitable. The fact that they might indeed be extremely powerful should only be important when there is no other option but for them to step in and do something but they should otherwise try to avoid conflict.

The  edgelord character "can" work in a "solo" story (see Berserk for a prime example), but for an RPG with multiple "main characters" (the PCs) it is usually counter-productive, as introducing an extremely powerful character who is clearly and always more powerful than them takes away from the centrality the PCs usually need to have in order for the game to be fun, and might make players thing "Man, why doesn't this person does everything then, if they are so powerful? What are we even doing here?", especially if the NPC in question is not showing any kind of restrain or doubt in their actions.

I feel it is also usually a matter of how they are presented visually that defines them as edgelords, so better avoid spikes, black equipment all over the place (unless that's something they are famous for in the game world for some reason or another), particularly impressive and "dark-themed" weapons or armor and the like.

There is a very fine line between "troubled-yet-interesting-and-useful" NPC and "cringelord", one that is not really easy to run on.

Disclaimer: the above is obviously just my opinion, I do not expect anyone to agree by default.

Some of LeK's descriptions remind me of an old text-ish adventure called Leather Goddess of Phobos.

Now, I can't stop thinking about edgelords of cringe (a phrase I've learned ITT) in the same flavor Dr. Frankenfurter. 🤣

"Troubled-yet-silly" NPC and not cringelord.

I think Lek made some great points. As awesome and dark as your NPC's backstory may be, try to avoid ramming it down your player's throats. They can tease her backstory out of her bit by bit as the story progresses, with occasional help from you to move things along. I think a little bit of mystique can go a long way in encouraging that sort of dialogue between your players and NPC as well. Allowing them to grow attached to this character before knowing her dark history in all it's detailed "glory" might even make it more dramatic. Granted, I've never DM'd a session in my life and I could be way off!

No other answer than 'depends'.  Some might be consumed by their tragedies, some may say :Well, that's in the past" and move on with their lives, most probably somewhere in the middle.

My most tragic character was a Shadow Sorcerer was abandoned as a baby in the trash, taken in by a lovely couple who sheltered him when realising how strange he was and then his powers made him accidentally kill a puppy and they began to fear him. When his powers escalated his mother killed him and they buried him in the garden. Yet, having a soul literally bound to the realm of shadow and death, he didn't fully die and came back to life where he ran away. He lived on the streets struggling to survive. He was taken in by a sorcerer noble, who taught him to use his magic and lived an ok life until this "new mother" died of illness. So off he went on adventure. Then he drowned. Then he came back. 

Normally would be ultimate cringe edgelord except he was actually an upbeat person, optimistic and a bit of a prankster. His feeling was, shit happens, life is weird, not worth moping about so get the feck on with it and live your life the best you can. 

He was great, until a TPK ended the campaign and we began another.

Much like Cyb3rMind, I play a Shadow sorcerer with a tragic past that is also a Fallen Aasimar. But he's an upbeat kid that always tries to find the silver lining in things.  Despite never talking about his past, always smiling, and being generally pleasant, any time he uses his Shadow powers or Aasimar's Necrotic Shroud ability, I get jokes from everyone else about being the edgelord goth kid.

My point is that it is an internet stigma that can't really be escaped. Play the character (or NPC) true to your concept and let everyone else worry about how they view it. 

First mistake was asking reddit literally anything, most of the people there are just making jokes. And I, for one, am sick to death of the overuse of the word "cringe".

Play your character true to concept, no holding back. The best villains are ones your players hate. They may make fun of you, but after you make them suffer? They won't. 

As far as using op npcs, I do it all the time. My players, if they are meant to defeat them, either

A) level up. A lot.

B) need a certain artifact or weapon.

I'll give you an example. I made a lvl 20 npc villain with a 30 for all stats, advantage (and expertise) on every save, and 27 ac. He met the party when they were lvl 6. He flexed, and told them to run. All but 1 player did. The one that didn't? Torn in half.

The point is, don't let immature, skyrim-raised (video games and tabletop are not the same thing!), buzzword-spouting losers ruin your game.

7 years later I wonder if he ever figured it out

Threadnomancy aside, it's an interesting discussion.

I have 3 characters which spring to mind as having a seriously dark and twisted past, which I'll happily ramble about.

Players of the Cheese Chase campaign, if you're here, I recommend not reading further!

The first is Gizmo Grayling, a gnome who runs a magic item shop in my world. He's an NPC (originally a throwaway character I played, then he evolved a lot). Gizmo is quite cheerful, ever-helpful, fairly money-grubbing, and secretive individual. He never leaves his shop, though, and a few of the phrases he's used have put an awkward dampener on the party, or left them a little confused. One example being his artificed semi-sentient assistant, which extends from the ceiling to help him (similar to GlaDOS). The party artificer jokingly said "How much did that cost?", and Gizmo, harrowingly, replied "Everything.", then refused to elaborate.

Gizmo's background is that he was an artificer in the employ of a huge organisation, who had him creating magical weaponry to supply the world. The company also had him working on the possibility of storing sentience in gemstones, which he successfully achieved, saving his only daughter from a short life of crippling disease, with a view to build her into a warforged body. The company swooped in, seized her as an asset, and tried to kill Gizmo when he resisted. He escaped into the facility, and he brought it down from the inside - setting loose the experiments to cripple the entire facility and destroy everything. Barely escaping the horrors with his sanity and his life, he then used his greatest creation - the Chalk of Labelling, which makes anything written with it true, and wrote "Home" on a door, to escape. Instead, he emerged into a liminal space, a workshop where he could continue his work, which backs ever onto the facility. Home's where the heart is, and without his daughter, he can never leave. Gizmo is stuck in this torment, his daughter so close, but the horrors he unleashed within the facility keeping him from ever going back to get her.

Gizmo stays cheerful and friendly, but his past has left him despondent and crushed, which he masks behind the cheer. His experiments are unhinged and dangerous, but he somehow never gets hurt by them. I play his character with an ear always for things which will hint at the horror of his backstory, but I don't throw it in people's faces.

Second is my PC named Dusty, who's a halfling warlock/druid who, in short, was fleeing the flames of a wildfire which he accidentally started, and which consumed his home, and his wife. He was cornered, and destined, and whispered to the world, for anything to hear, "Please, please don't let me die" - and the fire hesitated, and asked "Why?".

Now Dusty is a firedancer, using his magic to weave fire and smoke into pictures as he tells his stories to the crowds. His patron is the Fiend, and his wildfire spirit is his wife's soul, who returned to try and tell him it wasn't his fault. He is a slave to the flames, and fears for those who he associates with, and is terrified that if he ever goes back on his pact, he will lose his wife for good. I play his character as a good and nice guy, who can snap just like that. He's also utterly fearless, because he simply doesn't fear death any more than he fears his current life.

Now, the final character for this is the hinted villain of my campaign, Modi, who is the brother of one of the characters in the party. They both fell from Ysgard as babies and were separated - the player character landed in the material plane and was raised well by halflings. The other, however, fell to the Abyss, and was taken in by Dagon, the eldritch prince of knowledge. Modi grew up fed on knowledge, and where the PC forged armour fit for a paladin, Modi forged chains - chains which anchored his sanity, to allow him the great volume of knowledge he has. He knows everything of his and the PC's history, knows the life he was denied by the fates when he fell to the abyss. He has every reason to resent the world and everything in it, and he is working, by all accounts, to bring about an apocalypse. He acts disdainfully to the party, and knows he has a superior knowledge to them, but I have avoided making him cruel - he tends instead to assume they need no explanation, speaking plainly of things they don't know without context, which has led to them theorising based on their clashes. He has also offered them knowledge, offered them to join him - and has no spite in him. I roleplay him as utterly cold, the soul washed out of him by the waters of the starless sea of the abyss, regarding the party with indifference which has no arrogance in it. It's proven an effective way of making him seem genuinely scary, and several people have commented on how he is someone they really don't want to meet again (which is player talk for "when do we face him again!")