So I'm running my first 5e game (I know, I know, running a game just as 5e is closing out) and things are going pretty well.  I'm pretty new to the system but the players are happy, they are engaged with the story (I've been playing and GMing other RPGs for years) and its a story I am happy to tell.  However, as things go on, I realize I am going to NEED a few new monsters and I am just not confident in myself to make them and judge their challenge rating appropriately.  That's where I need help

I was hoping some of you out there who are more into the monster creation side of things could help me generate a few monsters, maybe just until I can get the hang of it myself.  In particular my campaign involves Mind Flayers socially evolving and starting to better themselves by (essentially) taking class levels.  I'd like to have stats for a mind flayer Fighter (Psi Warrior Inspired), a Mind Flayer Rogue (Soul Knife Inspired),  a Mind flayer cleric (Maybe Order-inspired?  As in imposing order on the universe?), and a Mind Flayer Sorcerer (Abbarant Mind inspired, obviously)

If you want to tone down some of the more problematic Mind Flayer abilities (their cone blast disable everyone thing) that would be fine, you could say that they are 'diverting' their mental energies from their baser instincts into things like forming psychic daggers, or forging a psychic connection to their Elder Brain so strong that it creates cleric spells. 

Anyway, I'd just love to see that and would appreciate it.  Let me know if I could do something in return.  I'm pretty good at coming up with unique magic items if you want to trade talents.

What kind of CR are you looking for? What level are your players and how many of them are there? What all else are you planning to include in the encounter? Info like that is kinda important for us to know how much to tack onto the flayers for you.

I'm variable on CR.  Currently the players are four level 4, but I'm certainly not going to send my players up against mind flayers at that level!  I'm posting this early just to hope to get a few people interested. 

I'm hoping to use them repeatedly, like maybe if one is CR 8, maybe one at party level 7, and then maybe as the players level up they face a few more of them at a time.  I'm looking for them to be reoccurring enemies.

Recurring enemies are tough, most players get super frustrated whenever an enemy escapes, especially more than once. I’m working on a Mind Flayer Psi Warrior for you, probably gonna end up around CR 9-10. By itself it should be a nice, solid “deadly” encounter for a party of 4 13th level PCs, or almost a whole day’s worth of challenge for a party of 7th level PCs. If you want things to be a li’l easier it’ll definitely require nerfing the Mind Blast.

Oh, sorry, no reoccuring as in, more than one of them.  Like, the Mind Flayers have a training program to turn out warriors and rogues and such because just relying on their base abilities isn't getting them their evil astral-sea-spanning empire back. 

Ahh ha ha. That makes sense. Well, I hope this helps:

Quote from IamSposta >>

Ahh ha ha. That makes sense. Well, I hope this helps:

 Wow, thanks, that looks great!

Oops!! Sorry, I forgot a couple of things when I made that. It should have 3 more Hit Dice (and therefore a few more HP), and technically it should also have proficiency in two more skills and both Str & Con saves as well. My bad yo. I have updated the statblock I made to include the additional Hit Dice & HP and the skills, but left the Save proficiencies off since that would make them basically proficient in every save except Dex. I also realized I forgot to update the skills, attacks, and save DCs to reflect the higher PB, so I fixed those too. If you want it, I can share the statblock with you, it has all the rollables programmed already and everything. All you need to do is PM me with an invite to a private campaign for two and if you have a subscription you will be able to add it to your collection after I send you the link.

I also took a look at the Soulknife to add to a mind flayer, but half of its 3rd level abilities won’t really help much at all. If it were me I would instead do a slightly modified version that streamlines things a bit. It’ll be easier to run than adding the full on class levels. I’ll post that here for you too in a little bit.

Here’s the “psi rogue” I whipped up:

As you can see I replaced the blades with a “psi bolt” since the tentacles are already way stronger as a melee option, and I skipped Sneak Attack and just rolled an extra d6 into each psi bolt to compensate. I also skipped the Psychic Whispers since it’s complicated and the mind flayer already has telepathy, and I skipped the psi-bolstered knack since I know from experience that it’s a bigger pain in the 455 on a monster than it’s worth.

Quote from IamSposta >>

Oops!! Sorry, I forgot a couple of things when I made that. It should have 3 more Hit Dice (and therefore a few more HP), and technically it should also have proficiency in two more skills and both Str & Con saves as well. My bad yo. I have updated the statblock I made to include the additional Hit Dice & HP and the skills, but left the Save proficiencies off since that would make them basically proficient in every save except Dex. I also realized I forgot to update the skills, attacks, and save DCs to reflect the higher PB, so I fixed those too. If you want it, I can share the statblock with you, it has all the rollables programmed already and everything. All you need to do is PM me with an invite to a private campaign for two and if you have a subscription you will be able to add it to your collection after I send you the link.

I also took a look at the Soulknife to add to a mind flayer, but half of its 3rd level abilities won’t really help much at all. If it were me I would instead do a slightly modified version that streamlines things a bit. It’ll be easier to run than adding the full on class levels. I’ll post that here for you too in a little bit.

 Sure, they don't have to be full classes, just a hint to the players that the Mind Flayers are trying something new.

I know from experience that Metamagic and Font of Magic are not worth the trouble on a monster, and mind flayers basically already have permanent Subtle Spell, so I skipped it entirely. Here’s your Aberrant Mind Flayer:

Thanks so much man, these are great!