Goblin 4 goes down under Valar's sword. As does the goblin leader Squirch, his final words as he's teared apart by a bear: "Fight on fools, y'all can still beat em!" 

The rest of the goblins make a DC 15 CHA Check to see if they break and run: 14

They consider taking Squirch's advice and continuing the assault, but after what you all just did to him and Goblin 4, they shake their heads. "Let's go! Now!" And they Disengage as a Bonus Action, then Dash away from all of you. Screaming about bears and lions as they run. You also barely hear them say, "Hopefully they head after those Deadites to the church, and get killed by the Chuul in the basement as well."

Do you follow the Goblins or let them go? 

Thelanis will not begin pursuit, but will do so if one of her companions does.

Valar will hold his position

Amiz will also hold position and not pursue. 

Alsen will breath heavily, "Well done yet again. You really are quite formidable. Hopefully that's the last we'll see of any goblinoids down here."

If no one has anything else they want to you can finish off your Long Rest and set off again around the bend in the river in the morning. Here's your random encounter roll for he day: 12

You carry on down the path you've been following for the last couple of days. As you travel, Valar feels the pull of Helm growing stronger and stronger. Amiz and Thelanis feel a different emotion. They begin to feel a darkness come over their mind. Pulsing and violent, it begins as just dark thoughts. But you would have heard that this is symptomatic of the madness that goes along with general proximity to the city of Kholias. They must both roll CHA Saves to resist a Madness effect. Interestingly, Draíocht seems unaffected by these thoughts:

Amiz DC 10 CHA Save: 17

Thelanis DC 10 CHA Save: 18

Both Amiz and Thelanis are able to keep on top of these dark thoughts. 

After the day's travel, you reach another bend in the river. However, while the last bend you had to follow the water, at this bend you find a bank leading up and away from the river. You'll spend the night here, but in the morning you'll need to make a choice:

Follow the river bend to the right, or head up the embankment and away form the river to the left?

"A fork in the path, my friends," says Thelanis, looking at the Kuo-toa's map. "The right leads to the elf camp, a considerable distance away, The left is the 'weird church' where I suspect the "deadites" are our necromantically involved friends and a 'chull', whatever that is. This headache I have has me spoiling for a fight, so lean towards the western path, what do you all think?"

[[drumdigby: I had Thelanis roll an arcana check to know what a chuul is. She rolled a 16, and religion and nature are the same score. If she does know what a chuul is, I'd like it to be a bad memory she's trying to avoid dwelling on, which is why she is pretending not to know what one is and deliberately mispronouncing its name. Her deception, if you want to offer insights to the party to tell she is lying is 10.]]

21

Draíocht takes to using mold earth to form makeshift cover for the camp during the night. As Thelanis speaks he pauses. "I've no headache, but I must admit this journey seems to have stirred a thrill for hunt. Ceasing the machinations of Mycette and Jagar seems a worthy goal and I would readily follow."

[[
Self-note: replace heat metal with lesser restoration as a precaution against Amber Decay should we go to the church.
]]

Valar continues to support the decision of linking up with the Elves, before tackling the church. While in camp, he will make his nightly absolutions to Helm to prepare himself for the challenges to come. 

Alsen also wants to go after The Eaters, so assuming he gets a vote, it's decided you'll be going to the church. He will warn you all though, "This won't be a hunt, it will be a bloody fight to the death. The Eaters do not go down easy, and they... do things... to the corpses of their victims." He grimaces as if in pain at that comment.

You all climb up the embankment and walk away from the stream. Here's your random encounter roll for the day's travel: 3

You travel for a number of hours and then come to a cliff looking over a clearing in the distance. In the middle of the clearing you see a building that can only be described as a pure white, clerical looking church.

Valar feels the immense pull of his god, and Draíocht seems to be less effected by the madness, so here's Thelanis and Amiz' DC 10 CHA Saves for madness:

Amiz: 9

Thelanis: 9

91

Both Amiz and Thelanis start experiencing extreme hallucinations. Pictures of horrors from places you've never even dreamed of start to formulate in both your minds. You both have Disadvantage on Ability Checks for the rest of the day.

Valar looks at his comrades, assuming he suspects the same dark thoughts that invaded his mind. He will try to channel divinity to see if it can counter the effect on their minds

“Not sure how much good that will do, the bargain I made for power may be offering a direct route to my mind.”

He nods, knowing what impact those dark thoughts brought

I’d say if you want to mark off a Channel Divinity, you could put off the dark thought for at least the day. Up to Valar.