Wangji doesn't have time to reflect deeply on what a terrible plan this probably is because the moment he catches the sword from the air he's in motion again. The Wen soldier closest to Wei Ying he cuts down in seconds, the next one he strikes hard across the chest with his torch -- there are a lot of soldiers -- 

-- okay, if they're trying to kill the Wens now then Zixuan definitely doesn't want to be left out. He will try whacking guards with a torch until he can wrest a sword free from any of them.

The other Jin disciples, alarmed and surprised, make an uncoordinated effort to rally around him. Several are struck down by guards immediately, which causes others to panic and fall back into the broader cavern.

This got dangerous and out of control VERY QUICKLY and all the guards are having a terrible time! Most of the terrified unarmed disciples are also having a terrible time! The guards focus their attacks on Wei Wuxian, but this entire brawl is unfolding rather chaotically. 

Wei Wuxian will continue to fend the guards off, trying to disarm them.  As soon as there's enough of a break in their attacks, he's going to pull the talisman off of Wen Chao, yank him to his feet, and put the sword to his throat.  He begins walking Wen Chao towards the pond.

Wen Chao is led into the darkness with no idea where they're going.  He doesn't like this plan, but also doesn't want to get his throat slit by struggling.

"If you kill me, my father will destroy you in retaliation," he whimpers.

Wei Wuxian is beginning to regret not picking his torch back up.  Hopefully he remembers his way through the cave well enough.

"I certainly expect him to try."

He can reach the pond without tripping on unexpected rocks or colliding with unexpected walls! Conveniently, the brawl spills deeper into the cave after him and provides moderately better lighting. Lots of people are swinging torches and shouting very loudly. Several already lay dead or injured on the ground. A trio of guards close ranks around Wang Lingjiao and retreat nervously towards the entrance.

The majority of the Wens continue to rush after Wei Wuxian, and continue to be disrupted by Lan Wangji and the Jin disciples. 

Jiang Cheng has also managed to steal a sword.  The Wen guards are probably not going to hurt Wei Wuxian while he has Wen Chao hostage, so he focuses on just stabbing as many guards as possible so there can be more weapons for the other disciples to pick up.

Alright.  Pond, Xuanwu of Slaughter, Wen Chao.  He kicks a nearby rock towards the water and begins to shout.

"Hey! Wake up!"

A groaning rumble fills the cave; the rock mound in the center of the pool begins to quake.

"Wei Ying!" What are you doing?

He kicks another rock towards the pond.

"Hey! Over here!"

Lan Zhan can yell at him about this later, when Wen Chao is dead.

A giant serpent-head rears out of the pool, sloshing water everywhere. The rocky island of a shell lurches as the tortoise moves, looming towards all the noise.

Several of the skirmishing disciples scream.

This thing is attracted to blood, right? He's going to walk forward, as close as he dares to the Xuanwu of Slaughter, and, very quickly, shove Wen Chao forward, slashing the sword along his back as he does so.  As soon as he's no longer holding Wen Chao, he's going to back very quickly away from the Xuanwu of Slaughter and back towards everyone else in the cave.  How's that fight going?

The Xuanwu of Slaughter lunges agreeably at Wen Chao.

Meanwhile, the fight is going pretty well for the rebelling disciples. There are more of them left standing than Wen soldiers, at the moment, and at least half of them have managed to obtain swords by now. Wang Lingjiao and her guards appear to have successfully absconded; they are no longer in view.

Wen Chao does not successfully fight off the Xuanwu of Slaughter by himself.  There is a lot of terrified screaming coming from the darkness as it shakes him around like a rag doll.

A loud crunch sounds through the cave, and then Wen Chao is no longer screaming.

The Xuanwu splashes its way towards the shore, head swiveling towards the loudest clashes of blades. 

Well, that's that problem solved.

Now he has to deal with the Xuanwu.  He runs back towards the other disciples.

"The thing we came to fight is here!  We might want to get out now."

Hopefully this time he can avoid getting trapped in a cave for a week.

He is met with strong agreement and lots of movement! The other disciples are very on board with moving further away from the Xuanwu.

Wei Wuxian will head back towards the cliff they came down in a hurry with the rest of the disciples!

They're too late. Wang Lingjiao and her retinue have already cut the ropes.

"They've cut the ropes! We're stuck down here. We'll have to find another way out!"  Hopefully without getting stuck down here for a week, this time.