No indicators tell you where these doors and passage might go. Might as well choose one and get crackin'.

What exactly is Wripers looking for?

Quote from Raccoon_Master >>

No indicators tell you where these doors and passage might go. Might as well choose one and get crackin'.

What exactly is Wripers looking for?

 You're making it sound like Wripers knows.

As if he know's which door to go through? Or whether to head down the passage? This place does seem vaguely familiar but he can't quite place it. 

Kass decides that he doesn't like leaving doors behind him without knowing what's beyond. He'll go to the first door to the left of where the group entered, and open it, stepping back swiftly to avoid any surprises. 

Quote from Raccoon_Master >>

As if he know's which door to go through? Or whether to head down the passage? This place does seem vaguely familiar but he can't quite place it. 

 More like he's not very bright and he might just be sniffing around for no reason, whatsoever. But if he does spot something, great. Maybe Amari'll give him a treat. 

...he's not the sharpest knife in the block, what can I say?

Amari rifles through her pack, finds a bit of hardtack soaked in bacon grease, and tosses it to Wripers. She then turns her attention toward the door that Kass has just opened. 

Kass opens the door, stepping swiftly back, and it was a good thing. A burst of rainbow energy shoots out from behind the door in a technicolor burst. Unluckily, someone was examining the door opposite the one Kass opened and got blasted.

DM Roll: 1

Targeting roll: 3

Can I have Ruin make a DC 22 DEX save as purple, blinding light strikes him?

A DC 22 Dex save...

12

If it does Poison or Necrotic damage, Ruin has resistance to that. If it is Acid, Cold, Fire, Lightning, or Thunder damage, he'll throw up an absorb elements to gain resistance to it.

As the blinding light surges forward, it splits into two crackling bolts, each of which strikes Ruin in a mechanical eye. He is now Blinded. And please make me a DC 22 Wisdom saving throw.

What is the rest of the parties response to this?

Wis save: 28

"This is most unpleasant," Ruin mutters.

Then he casts lesser restoration on himself, ending the blinded condition. 

Kass looks apologetic.  "Sorry, my friend - but at least we now know to open these doors carefully."  Kass takes a look into the now open door, assuming there isn't still a beam of energy pouring from it.  

Wripers is standing nearby, macking on his treat, just a sort of bystander. He watches the procession in a sort of lackadaisical mid-meal contentment. He looks at his last bite, soaked in drool and bacon grease, then offers it to Ruin.

...a second later, he thinks better of it and takes the last bite. He shrugs at the big metal guy and walks off.

Ruin is not affected by the secondary effect of the magic. Tank-fully (see what I did there? Since he is a tank?)

Behind the door that Kass looks into, which is indeed no longer spewing forth dangerous magic, is a blank wall, with a faded glyph inscribed upon it. If Kass had to guess, they would say the trap is similar to something like a Glyph of Warding. 

Keep in mind, besides the doors, there is also the passage to the east which branches off into the darkness.

"No more doors then?" suggests Amari. 

Maintaining her invisibility as she approaches the passage to the east, she calls to the others. "This way. I'll scout ahead a bit."

Amari moves down the passageway but goes no farther than 60' from the others. (Stealth 20)

Kass stammers a bit.  "But, but... all these other doors, they might not all be trapped... oh, never mind."  He trails off, then follows Amari, also trying to move stealthily but giving her plenty of room, about thirty feet behind her.  

Stealth: 27

Wripers just follows, too oblivious to focus on stealth, but aware of even the slightest drop of a pin. 

The passage you head down splits into two different branches, one heading north and the other south. Which way do you go?

"If we have no way to determine which path is better, perhaps we should leave it to chance," Ruin says. "We can flip a copper piece to determine which path we take next."

"Sounds good, Ruin."