Let's get right into it.  Three recipes discovered from the archives, plus my take on it.  Use these simple recipes to warm your soul and keep the liquor cabinet well stocked.

My take on the Jack Knife doesn't add much, but what it adds makes it something just for me.
1/2 oz Jack Honey
1/2 oz Bailey's
1/2 oz Wild Turkey American Honey liqueur
​1/4 oz Drambuie

TASTING NOTES
​+ I like my whiskey with honey, so the double tap of Jack and Wild mixes well.
+ Bailey's is always a win.
+ The Drambuie just smoothes it all out.

Shoot well.  Never straight.
-Adamus

I've been running campaigns long enough that I've stacked up NPCs like Pokemon cards, ready to unleash them onto unsuspecting players.  Sometimes they work wonders, other times they suck wind through a straw.  Let's take a look at a few and see what I could have done better.  

Core Concept: Jedrek is a one-man army.  Built by a broken monastery as a final solution, a Blackweave monk wields the power of the broken weave.  Using his skin as parchment, a Blackweave covers himself in arcane runes and tattoos, each connected to an ancient power.  By engaging a tattoo, he can cast the spell that was inscribed upon him, wielding the cosmic powers of the lost tribes of wizards.  But once the tattoo was spent, the ink burns off of him, lost forever.
  A Blackweave can add permanent augmentations to his body by inscribing runes upon the skin, and burning them over 100 days.  These marks become infused scar tissue, sewn with residual power.  One can use this technique to add extra ways to manipulate their Ki, make their bodies more formidable, or make their minds sharper.
Version 1.0: A Way Of The Long Death Monk at Level 17, with a Level 14 Gunslinger as backup VS a party of five level 10 adventurers.  Low Con saves and lucky rolls on my end put the melee friends on the stun train pretty fast, but things got pretty close.  A Tattoo of Contingency - Revivify was placed on him as a last resort by his Compendium (the order branch), which saved his skin.  Using Step Of The Wind, he escaped, healed, and returned for his quarry, killing a PC and taking the body. 
  Notes: It was a tough encounter and a decent field test for the build, but he didn't use a lot of his tattoos.  As it stood, his action economy required use of his Bonus Action to engage a tattoo.
Version 1.5: The players, now at full force: 10 characters at Level 13 VS 1 Level 18 Long Death Monk.  Taking no chances, the resident pyro cast instead Telekinesis, holding Jedrek aloft and restraining him.  As Telekinesis is a contest of checks, not saves, Jedrek's Diamond Soul (proficiency in all Saving Throws) doesn't engage.  Good job party!  However, because of one small wording technicality in Jedrek's build language...he wasn't entirely shut down.  He still had access to ALL of his Weave, so every round he'd struggle against the Telekinesis (fail), then spend a Bonus Action to engage a spell that was laced onto him.  It was a "chip damage" fight; still interesting and dangerous, but felt off somehow.  It also took a long time.  They killed him and burned the body (evidence), and felt good about avenging their ally.

Future Adjustments: We finally figured out what was bugging me.  Engaging the tattoos can still be a Bonus Action, but I propose a few limiting factors.  Certain on 1 and 2, entertaining 3 and 4.
1) He has to touch the tattoo, which requires movement.  If he's restrained, he can't do that.  Telekinesis should have shut him down completely.  It's the anti-monk spell!
2) There should be a Ki cost to engage the spell.  Either Spell Level = Ki Points spent or 1/2 Spell Level (rounded up) = Ki Points spent.  Cantrips are always 1 Ki Point.
3) I'm considering a spell level limitation.  Like no spells above 7th...  Then again, even with a 20th level monk, using 9 Ki to cast that crazy Meteor Swarm that others at my level can also crank out ...as a Bonus Action...  Yeah, no.  We're limiting this crap.  No 8th or 9th level spells.  7th I MIGHT be okay with.  We'll play with it.
4) The Runes he's burned take up attunement slots, or 1/2 an attunement slot.  They take a lot to get, including cost and training (100 days, remember), but they *are* permanent; so someone with a lot of time and resources can add on Runes easily.  They already have a maximum of 3 Runic Augments before their body can't take the strain anymore, but after that we've got Bracers of Defense, a Ring of Protection, and a Cloak of Protection (a total +4 AC, and a total +2 to all saves).  With Runes that make your Martial Arts 1d12 (instead of 1d10), allow you to Hunter's Mark, and others that grant you Sneak Attack for Ki...  Don't want anyone to get too beefy too fast.
Why?: Action economy is too far broken.  He can be a better wizard than a wizard, and still PUNCH REALLY HARD.
Is the Blackweave dead?  Nah.  But it requires more tweaking as a subclass.  Monks have A LOT of options already, so it may serve better in another class (Ranger could be interesting), open-ended to all classes (needs some secrecy), or needs a few more limitations/refinement.

Core Concept: The Daughters of Syn had been a consistent villain group all throughout campaign 2 on Tuesdays, and I'm a big fan of using common mythos and turning it on its head.  In this case, we're using the Seven Deadly Sins as our model.
  "Sly" is Sloth.  Laid back and lazy, this knight doesn't want to do much, instead opting for her familiar, Freya, to do most tasks for her.  But for all her laziness, if ever you were to hurt Freya, or try to hurt her more severely, she would finally show you her true power - frightening and efficient, she'd like to end the fight as soon as possible, so she can return to her nap.

Encounters and Impressions:  Sly was my absolute favorite side villain.  Every moment the party encountered her, they fell in love with her dry wit and lack of commitment.  She would often show up on the outskirts of a battle (showing that she was always watching for her mistress, Syndrosa), smoking a pipe and giving raucous commentary of the fight, quick to crack jokes or just shrug at veiled threats.  In fact, the first time she met the group, she helped most of them escape the Underdark (I wonder if that endeared her to them a bit).  She was really just gathering information on them at that point, but she really didn't care either way, so killing them would be boring.

Fight 1: The first real encounter with Sly involved the group trying to rescue a little girl trapped in the Underdark.  Sly had an amulet on her person with a soul trapped inside (but the party didn't know that, only that she had a nice amulet, it looked valuable).  The party turned into bugs and snuck into her room, while others tried to deal with Sly's partner, an Oathbreaker Paladin named Naz (Pride).  For most of the fight, the party simply kept Sly occupied as she played with them, always at the edge of caring.  It wasn't until Naz was killed that Sly began to show her true ferocity.  Sly's first boon involves Freya; the fire fox fuses with her form, granting her lycanthropic strength and speed, as well as some Greater Invisibility.  Couple this with the fact that she's already a Level 16 Druid by now...and we've got something serious on our hands.  The party has A LOT of close calls, but manages to kill her, her form crumbling away in strips of...ice?

Fight 2: MUCH TIME PASSES and the group assault the now Queen Syndrosa in her OWN LAIR, and are promptly defeated.  Despite this Full Party Capture moment, the players were SO HAPPY to find out that Sly was indeed alive, and the version they killed was some sort of Clone or Simulacrum.  Heck, she even helps them escape the follow-up encounter (again: she doesn't really care).  But upon returning to the Fortress of Syn, now better prepared and after taking out Lust and taking some weapons from Wrath, they come across the real Sly.  She toys with them a little...and then the Paladin kills the fire fox.
  A Storm of Vengeance, and A LOT of near-death experiences (2 deaths total, but yay Revivify), a well-timed Power Word Kill drops Sly for good (strange, she could have totally Counterspelled, but she didn't...).  The party was the SADDEST I have seen them after this fight - they didn't want it to end!

Build and Boons
Class: Druid 20, Circle of the Moon (not that she cares)
Standard Boons: Boon of Fortitude (HP +50, Temp HP Ward +20), Boon Fey Step (Movement +30 as a Misty Step)
Boon of the Fire Fox - grants the Knight a familiar in the form of a fire elemental.  This familiar can heal you from a distance and merge with you to grant extra physical bonuses and a burst of fire damage at the end of every one of your turns.
Boon of the Sloth - Aura of Relaxation (little things don't stress you out, Calm Emotions at all times, advantage on saving throws against being charmed).  Social power of Disarm (disadvantage for foes to resist your relaxed charm).  You have entertaining and informative visions involving the people you observe; you no longer sleep, but napping opens these visions to your perfect memory.  Whether you act on them...is totally up to you.
Is Sly gone for good? - Mmm.  Tricky thought; death can get weird in D&D, and resurrection moreso.  Depends on where her soul ended up, and who cares enough to get her back.  I have a feeling her return would not be an unwelcome one, at least by a few PCs. ;)

Core Concept: A Circle Of Spores Druid hell-bent on conquering the world of beasts, controlled by the Mantle of the General; an ancient artifact forged by the Erlking of the Feywild.  Woof.  That's heavy.
  Anox was a product of the Erlking's choices; after the Archfey took the Helm of the Hunt, his purging Valkyries decimated the forces of Anox's predecessor, Gurlanik, the Fade.  To rectify this, Anox used his only son as a lure to other beings touched by Fey energy, and used his Circle to "seed" them with necrotic powers - and his control.  The resulting Treant-Hybrid army, coupled with the stolen Mantle's innate power to call nearby beasts under his command, Anox began preaching dominion over the Wilds beyond and amassing an army of druids who shared his ideals.
  His son, Darius, finally fed up with the loss of innocent life, formed his own pack of druids - attempting first a coup, then, when that failed, an all-out-assault upon his father, while freeing those that would be hunted for his dark purpose.  This betrayal marked the beginnings of Anox's madness, and the Mantle began to wrestle control away where it could.  Soon, the two entities became indistinguishable from one another, and the more Anox used the Mantle to augment his magic, the more it took from his mortal body...but he could not die as long as it was bound to him.

Boss Fight: This fight was...problematic.  There was a spore lair with infectious actions, a whole one on one duel where the PCs made strange tactical decisions and then got mad when they didn't work out.  And this was already a difficult campaign to run; huge mix of experience levels and play styles clashing all over the place.  If I were to run this in the now, 4 years wiser, I'm confident it would have been earned.  Honestly, I was still cutting my teeth on this one.
    There were personal stakes with a PC, which, in any other case, would have made this much more charged - the end result here...was confusing.  Misinterpretations of rules and descriptions, intentions, and flow; it got pretty awkward at times.
  What I WANTED to happen was a dynamic battle of shifting landscapes and status effects, a ticking time bomb of spore growth, and a possible moral quandary of tearing the mantle free to destroy it or don it yourself.  Instead, it was a jumbled mess with a few great moments (I'll give that to my seasoned players), tarnished by that constant confusion or rules-lawyering.  Different group, different time I guess.

The Build: Druid 18 [Circle of Spores], Warlock 2 [Great Old One*]
  The Warlock element of this build required a lot of homebrew.  This Great Old One ends up being the Mantle itself, a semi-sentient immortal object (one of my "Legacy Artifacts") that has held many hosts before, and draws power equally from the Shadowfell and the Feywild.  It had regenerative properties, negated by radiant damage, and the Mantle has its own suite of innate daily spells - it could even cast additional spell effects by placing levels of Exhaustion on its user.  
  At the time, I wasn't confident with custom Legendary Actions, but a second go would simplify Anox's action economy to that of a standard druid, and the Mantle would act with Legendary Actions of its own, illustrating the dichotomy of the two entities joined.  I could then drop better hints as to the artifact's nature, and I would allow the PCs to attack the Mantle directly, adding a puzzle to this duel of fates.
  As it stands, Anox - and myself - learned a lot from this boss fight, and we haven't seen the last of his character.  Perhaps a new version will retcon the old for us all. 

Anywho.
It's important to look back now and again.  To consider where our lessons lie, and what new adventures we can craft with them in mind.  Maybe I'll do this again - I've got plenty stashed in the mental basement.

If you enjoyed this, maybe say so, or check out the Patreon (it could always use some love).  
Stay warm out there.
-Adamus