Here are some ideas, hope they prove useful.

-[Nimble] -> Higher dodge / Higher speed
-[Sluggish] -> Lower dodge / Lower speed
-[Blind] -> Lower accuracy / Lower critical hit chance
-[Eagle Eyed] -> Higher accuracy / Higher critical hit chance
-[Feeble] -> All stats are lowered
-[Mighty] -> All stats are higher
-[Vigorous] -> Higher HP
-[Frail] -> Lower HP
-[Resiliant] -> All resistances are higher
-[Sickly] -> All resistances are lower
-[Bloodied] -> Adds bleed to attacks / Higher bleed resistance
-[Venomous] -> Adds blight to attacks / Higher blight resistance
-[Disease-Ridden] -> Increased chance to spread disease
-[Overwhelming] -> Higher base damage / Adds stun chance to attacks
-[Aggravating] -> Attacks decrease stress healing recieved
-[Wasting] -> Attacks decrease healing recieved
-[Galling] -> Adds low stress damage to attacks / Lower base damage
-[Vexatious] -> Adds moderate stress damage to attacks / Lower base damage
-[Demoralizing] -> Adds high stress damage to attacks / Lower base damage
-[Vampiric] -> Recovers HP on successful attacks
-[Regenerative] -> Recovers small amounts of HP over time

Theres some cool ideas in there. I'll be sure to add some of them to my idea list

Updated my prefix list with some of your ideas. Be sure to check it out

Some more ideas, though this time more for certain types of enemies, though undoubtedly they could be shared:

Bone Rabble / Bone Soldier
-[Crumbling] -> Lower resistances / Lower stats / Lower base damage
-[Trained] -> Slightly higher protection / Higher base damage
-[Freshly Risen] -> Higher speed / Higher resistances
-[Ancient] -> Higher resistances / Lower HP / Higher base damage / higher CRIT chance / Higher stats
-[Rotted] -> Lower HP / Attacks deal light blight damage / High blight resistance


Bone Courtier
-[Decadent] -> Tempting Goblet now inflicts blight and reduces blight resistance instead of dealing sanity damage / Knife in the Dark deals lower base damage and now inflicts bleed
-[Frugal] -> Lower resistances / Lower HP
-[Vile] -> Deals higher stress damage / Higher CRIT chance / Lower speed
-[Highborn] -> Higher resistances / Slightly higher HP / Higher base damage / Drops more valuable loot


Bone Arbalist
-[Sniping] -> Higher crit chance / Attacks mark the target / Lower speed / Lower dodge
-[Crippling] -> Attacks lower the dodge of the target / Attacks lower the speed of the target


Bone Defender / Bone Captain
-[Heavily Plated] -> Higher protection / Lower speed / Lower dodge
-[Rusting] -> Lower protection / Higher speed / Higher dodge


Bone Spearman
-[Corrupting] -> Lower base damage / Attacks deal mild blight and stress damage / Lower stun resistance
-[Vileblood] -> Lower base damage / Attacks deal mild bleed and stress damage / Lower blight resistance


Bone Bearer
-[Blasphemous] -> Abilities now deal mild stress damage to the entire party
-[Rallying] -> Abilities now increase the resistances of all allies / Abilities now increase the speed of all allies


Ghoul
-[Vileclaw] -> Rend now deals blight damage instead of bleed
-[Emaciated] -> Lower base damage / Lower HP / Lower protection / Higher speed / Higher dodge
-[Bloated] -> Higher protection / Higher HP / Lower speed
-[Pickman’s] -> Higher stress damage / Lower speed / Lower resistances

Well i like your naming but most of your prefixes either only buff or debuff the monsters. I want the prefix to both buff and debuff. Nice suggestions anyway

Oh, I made some just straight buffs or debuffs for variety's sake. I figured not every monster will be the same, with some being stronger or weaker than their kin. I thought it might also change priorities in combat, as an enemy that is weaker than normal could be ignored for a round, while a stronger version would require more immediate attention and focusing of attacks. I can try to avoid that and make it more mixed from now on, though.

Well i prefer mixed. Atm priorities are already changed though. Play tested for a while and you do target other monster over others cause of the prefixes

Ok, here's a new attempt, I hope this works better with what you had in mind.


Cultist Brawler/Gladiator/Champion
-[Vengeful] -> Lower dodge / Higher stun resistance / Higher debuff resistance / Constant riposte
-[Elusive] -> Higher dodge / Higher speed / Lower protection / Lower HP
-[Brutish] -> Higher base damage / Lower dodge / Higher HP
-[Reborn] -> Lower resistances / Higher HP / Higher base damage / Lower CRIT chance
-[Shrouded] -> Lower HP / Lower base damage / Higher speed / Higher dodge / Higher crit chance / Stealth
-[Rapturous] -> Remove bleed, adds mild stress to attacks / Higher speed / Lower dodge


Cultist Acolyte/Enchantress/Witch
-[Eldritch] -> Does higher stress damage / Lowers stress healing / Lower accuracy / Lower stun resistance
-[Awoken] -> Higher HP / Higher resistances / Lower speed / Lower dodge
-[Spiteful] -> Attacks lower protection / Attacks lower resistances / Lower dodge / Lower HP
-[Chosen] -> Higher resistances / Higher protection / Lower HP
-[Commanding] -> Attacks buff allies accuracy / Attacks buff allies dodge / Lower resistances / Lower dodge

I'll take a proper look this evening. Vengeful is a nice idea

Oh, this just occured to me, but since diseases are thing in this game, perhaps diseased enemies that have a chance to pass on their specific illness, similarly to the rabid gnasher (10% rabies) or ghoul (5% the worries)? The 'victims' would keep the same buffs/debuffs the diseases give, and perhaps certain enemy types, like swinefolk and beasts, are more prone to certain diseases than other types. Debuffs involving stress, of course, could be ignored by the enemies since they don't suffer from stress ingame. Diseases with higher debuffs than buffs could have a higher chance of spreading in order to balance it out, and especially so if they're described as plagues and such. Here's some examples:

-[Diseased (Grey Rot)] -> +20% Max HP / -10 Accuracy / -10% Damage / 5% chance to spread Disease (Grey Rot)

-[Diseased (Creeping Cough)] -> -20% Damage / 10% chance to spread Disease (Creeping Cough)

-[Diseased (The Red Plague] -> -75% Bleed Resist / -5 Max HP / -5% CRT / 15% chance to spread Disease (The Red Plague)

I already have Plague Carrier which has a chance to spread disease. I don't want to clutter the prefixes in the current stage since i already got a nice list to work with. Also i have found a way to make the monsters repond to on-hit and on-death. So you can make prefixes with the effect triggering when they get hit or when they die

Ok, I'll keep that in mind. This time I'll try to make some more generic ones that apply to types of enemies.

Human
-[Greedy] -> Slightly lower speed / Slightly higher protection / Drops larger amounts of gold and gems
-[Mad] -> Higher dodge / Lower protection / Higher speed
-[Insane] -> Much higher dodge / Lower protection / Higher speed / Chance to drop laudanum
-[Maimed] -> Lower HP / Lower bleed resistance / Lower speed / Higher dodge
-[Babbling] -> Deals light insanity damage on attacks / Lower dodge / Lower speed
-[Blue Blood] -> Slightly lower speed / Higher resistances / Drops random gem and/or trinket on death
-[Scrounging] -> Slightly lower speed / Slightly higher resistances / Drops 1-3 random supplies (bandages/antivenom/medical herbs)
-[Thieving] -> Slightly lower speed / Slightly higher dodge / Drops 1-3 skeleton keys
-[Religious] -> Slightly lower speed / Slightly higher resistances / Drops 1-3 holy waters
-[Pilfering] -> Slightly lower speed / Slightly higher dodge / Drops 1-3 random heirlooms (busts/portraits/deeds/crests)
-[Gourmandizing] -> Slightly lower speed / Slightly higher resistances / Drops 4-12 food


Beast
-[Feral] -> Lower CRIT / Higher speed / Lower dodge
-[Dire] -> Higher damage / Higher HP / Higher protection / Lower speed / Lower dodge
-[Starving] -> Slightly higher speed / Slightly lower HP / Slightly higher dodge
-[Ravenous] -> Much higher speed / Much lower HP / Much higher dodge
-[Filthy] -> Slight increase in chance to spread disease / Attacks deal light blight damage / Slightly lower HP / Lower resistances
-[Pustulous] -> Attacks deal mild blight / Higher blight resistance / On death, deals light blight to all allies
-[Toxic Flesh] -> On melee hit, deals light toxic to the attacker / Slightly higher blight resistance
-[Piercing Quills] -> On melee hit, deals light bleed to the attacker / Slightly higher bleed resistance
-[Chimerical] -> Higher resistances / Lower speed / Higher base attack / Lower CRT / Higher dodge / Higher protection


Bloodsucker (mostly based on Crimson Curse states)
-[Passive] -> -5% Stun, Blight, and Bleed resist / -10% Max HP / +1 SPD / Chance to drop the Blood on death
-[Craving] -> -10% Stun, Blight, and Bleed resist / -10% Max HP / +2 SPD / Slightly higher damage
-[Wasting] -> -10% Stun, Blight, and Bleed resist / -20% Max HP / -4 SPD / Higher dodge
-[Bloodlust] -> +25% Stun resist / +15% Blight resist / -10% Bleed resist / +25% DMG / +4 SPD
-[Miasmal] -> +33% Blight resist / Attacks lower blight resistance
-[Gluttonous] -> Higher HP / Lower dodge / Lower speed / Chance to drop 1-3 of the Blood
-[Engorged] -> Higher HP / Lower dodge / Lower protection / Lower bleed resist / On death, explodes and deals mild bleed and insanity damage to the party


Husk
-[Crumbling] -> Lower speed / Lower dodge / Higher chance to deal blight / Higher blight damage
-[Fractured] -> Lower protection / Lower HP / Attacks reduce blight resistance / Longer blight duration
-[Doomed] -> Attacks mark the target / Lower protection / Lower HP / Higher CRT
-[Immaterializing] -> On hit, 50% to activate stealth / Attacks have a 50% chance to activate stealth
-[Temporal] -> Higher speed / Acts twice per turn / Lower damage / Lower CRT / Lower HP


Stonework (AKA just Gargoyles)
-[Petrified] -> Lower speed / Higher protection / Higher stun resistance
-[Cracked] -> Lower protection / Higher speed / Lower base damage
-[Stoneflesh] -> Higher speed / Higher dodge / Lower blight resistance / Lower bleed resistance
-[Mastercraft] -> Higher HP / Higher base damage / Higher protection / Higher speed / Lower stun resistance / Lower dodge


Unholy
-[Defiling] -> Lower base damage / Attacks deal mild stress damage / Lower speed
-[Rotted] -> Higher blight resistance / Lower HP / Attacks deal light blight damage
-[Reforming] -> On death, entity will rise once more as a bone rabble or bone soldier
-[Necrotizing] -> While active, healing effects are reduced by 50%
-[Crumbling] -> Lower speed / Lower dodge / Higher chance to deal blight / Higher blight damage
-[Reaping] -> Lower base damage / Attacks can inflict Horror on the target
-[Faded] -> Lower dodge / Lower protection / Higher CRT / On hit, activate stealth

Hmmm stronger monsters but the pay off is more loot. Never though about it. Could be a good way balance things out

In a similar concept, you could also have weak enemies with large amounts of gold or similar loot, but akin to the Gatekeepers ingame in that they will attempt to flee combat from the second round of combat onwards. One concept rewards you for winning against a greater foe, the other rewards you for your speed and tactics.

- - -

-[Bloodless] -> Immune to bleed / Immune to bleed resistance debuff / lower blight resistance
-[Mithridatism] -> Immune to blight / Immune to blight resistance debuff / lower bleed resistance
-[Loggerheaded] -> Immune to stun / Immune to stun resistance debuff / lower speed
-[Infamous] -> All stats higher / Drops higher leveled loot / Rare spawn rate
-[Legendary] -> All stats much higher / Drops much higher leveled loot / Very rare spawn rate
-[Sticky Ooze] -> Lower speed / Lower dodge / On melee hit, reduce speed & dodge of attacker
-[Elusive] -> Cannot be marked / Higher dodge / Lower protection
-[Steadfast] -> Cannot be moved / Lower dodge / Higher protection
-[Horrific] -> Attacks inflict horror / Lower base damage

Updated the prefix list thanks to some inspiration i got from you