Oh awesome. Rolling for crit 1

(What about the spirit guardians damage?)

yup, didn't forget. will add it on the mind-flayer's turn barring something preventing it

OoC Squiggles turn coming in 30 min or so

(right, forgot that's the delayed one)

Squiggles moves to Q13 and snarls at the Mind Flayer.  "This does not end well for you. Go back whence you came should you choose to live" and casts Slow (Wisdom save of 17)

Celric commands his spiritual weapon to move south 20 feet and attack.

Mirror image roll (forgot about this before): 15

The spectral hammer connects, but with the last remaining illusory double, causing it to disappear.

Then Celric moves closer to engulf his foe in his spirit guardians, and calls to his god, “Bahamut, rain fire on my foe!” as a shower of flame and radiant energy descends onto the mind-flayer. The creature again seems to resist the full effects, but does appear to be injured by the blast (14 damage).

Brix, having seen Balian's arrows harmlessly pop out of the mind-flayer's flesh, decides to rush forward toward the enemy and attempt to pin him in place

Brix Grapple: 10

Opposed by Acrobatics: 22

Flinging his crossbow to the ground, the barbarian follows up with a punch to the prone and grappled mind-flayer's tentacled mouth

Attack: 22 Damage: 4

However, although the punch appears to connect, it does not seem to do any damage.

Enraged, the mind-flayer begins to repeat the incantation that produced the fireball (legendary action). (Squiggles, post if you want to counter... I'll hold off on making the DEX save rolls until you decide)

Flynt's mind struggles against the psionic power keeping him unable to act, but is unable to break free.

Squiggles moves to Q13 and snarls at the Mind Flayer.  "This does not end well for you. Go back whence you came should you choose to live" and casts Slow

WIS save 25

but the creature shrugs off the effect, with what you assume is meant to be a smile.

Holding off on the mind-flayer's turn until Squiggles decides whether to counterspell the fireball.

Squiggles will counterspell the Fireball 

In case the slot level was over 3: 23

WIS save vs Spirit Guardians: 14

Its would-be fireball fizzling out in its hands, the mind-flayer is assaulted by Celric's spectral spirits (19 damage). It raises its gaze from the ground toward Squiggles, and utters something incomprehensible-but-decidedly-evil sounding while gesturing with a tentacle toward the wizard.

Squiggles, make a WIS save (with advantage)

20 

In a tug-of-war between two powerful minds, Squiggles feels for a moment as though a psychic tentacle is wriggling into his brain. But this isn't his first enchantment spell, and he manages to keep reality straight.

Balian ( stunned; DC 18 INT save at end of turn to escape)
Shale (stunned; see above)
Jarl
Celric (concentrating on spirit guardians, round 3)
Brix (raging, 12 HP)
Flynt (stunned; see above)
Squiggles (chillaxin')
Mind Flayer (-77; grappled, prone)

IntST vs stun 19

(Hallejula!)

     "Oww!" Shale comes to his senses. "What did I miss?!"

Celric walks up to the probed opponent and stands over the mind flayer and says, “By the guidance of Bahamut, I will be the last face you see.” He then unleashes nearly everything he has.

spiritual weapon 

attack: 23 Damage: 4

Spirit guardians 20

Warhammer War priest attack

attack: 25 Damage: 4

attack: 24 Damage: 5

Channel Divinity: Divine Strike:5

crit2

Holy shit, Celric

(at the end of Balian's turn)

(legendary action) The mind-flayer lashes out with a tentacle at the surprisingly strong goblin pinning him to the ground (Attack: 16 Damage: 20), pinning the barbarian in turn and knocking him unconscious.

That's gunna leave a mark

(Plus another d8 for the SW crit?)