I move to d3 and look around nervously. "Alright goblin! Come and get me!" I shout. I cast minor illusion to make it appear as though  the 5-foot square in front of me is littered with a pile of dead goblin bodies.

(can’t make the floor in front look like that, but they can be stacked.)

Tanrick shouts at the leftover goblin as he makes it appear as though he has multiple dead goblins stacked on the floor. (They are about 4ft tall, but skinny, so you just have a bunch of stacked dead goblins.). If you could see it, you would know it was unphased by this.

After realizing the goblin was unaffected I scoff. "Coward." I say just loud enough for the goblin to hear.

(If we ready attacks, we can release them before the goblin hides again.  That way we don't necessarily have to search for it.)

Dex save: 10 Jathon will move as close to where he last saw the goblin as he can and will ready a javelin to throw at it when he sees it

Jathon struggles against the jaws as they hold him down. (Sorry, you stay still. Can’t see the anymore, it has cover from the jaws around you. You may use your action to make another dex save, DC15.)

potentially still Jathon, Boris, you’re up! Boris, wisdom save!

Attempt at dex save: 16

Jathon frees himself from the beasts clutches. It disappears beneath the ground again.

Borris! You’re up!

Not making the save, but I can try!

Hey, I did it!

Wis Save: 17.

"Borris has heard greater insults from a bugbear, you little cretin! Now get back here so Boris can break you!" Borris makes his way to Row A to look for the goblin(passively). If still nowhere in sight, Borris huffs and says, "Two can play at this game, goblin." He tries to hide among the pillars(6).

Hiding at B12.

At least it can't find me passively! Yay -5 in darkness.

(I believe Goblins have dark vision.)

(they do.) (sorry for not posting, I thought Borris only made his save and was waiting on him. You’ll get something in a sec.)

With the darkness of the arena, you see something move, but can’t tell if it is the goblin.

Death Save:2 Atom’s Simulacrum melts, and Atom’s soul is rejoined with it’s body at the pillar.

You all hear something (20) as the goblin appears behind Boris and whispers well you would know, wouldn’t you. (DC12 wisdom or take 3 damage and disadvantage on next attack.). It then disappears, into the darkness after moving away.

As Gremdor aims his bolt at the Goblin,  he feels funny again. (DC 12 charisma save before you attack the goblin)

Everyone, you’re up! Boris, wisdom save! Gremdo, before you attacking, charisma save!

Wis Save: 7.

Borris collapses.

Charisma save: 7

(Friggin' finally.)

Readied attack: 23 Damage: 6

Total crit damage: 13 force damage

(Added the previous damage on as a modifier to make things easier.)

Gremdor will then ready another blast.

"Alright, come out you little bastard!" I say, looking around as I ready my crossbow, waiting for the goblin to appear in range. (if the goblin appears in range, I will shoot it with my crossbow.)

Gremdor shoots at the goblin, but it has no effect. In fact, it looks as though it heals the goblin before it ducks into cover.

Tanrick is ready.

Borris doesn’t like jokes about his mum and squirrels, let alone bugbears.

Borris, death save! Jathon, you’re Up!

(As far as I'm aware, there's no spell or ability that allows you to heal from taking force damage.)

(And if there is a spell, I don't think the goblin would have any opportunity to cast it.)

(And if this was something you homebrewed, why?  Why?  Force damage is one of the least resisted damage types in the game, and giving some random spellcasting goblin immunity(?) to force damage against level one characters seems extreme.  Especially since that would basically just be to target the warlocks.)

(Not a spell, a monster feature. As a reaction, it can take a hit and negative the damage, and instead heal 1d6 hit points. You’re in for it now.)

(not homebrewed, it’s in Volo’s. CR1, it’s completely fair.)

(What monster would that be exactly?  I have Volo's, and have read through it completely, and never once seen a CR 1 goblin with 4th level spell slots and that ability.)

(Check your Pm’s.)

(Yep, my bad.  Disregard that.)