How to stop a balrog
First off, don’t go into the Mines of Moria. Don’t listen to Gimli. He doesn’t know what he’s talking about.
Trust Gandalf’s instincts. Especially don’t get suckered into entering because there is a mini-kraken in the pond right in front of the door way. I thought the dwarves were master builders? They put their mine entrance right next to a body of water? What about drainage issues?
If you do end up going in the Mines of Moria. Survive the cave trolls and the goblins.
Well then, it’s time to draw straws. Somebody is staying behind. Do you have a sapper in your crew? Someone with explosives experience. A wizard is great, but don’t waste your wizard. You’ll want them later. Unless the author needed a convenient way to get Frodo and Sam on their own.
What would it have looked like with Frodo, Sam and Gandalf traipsing through Mordor. Probably wouldn’t work right? They’d get noticed? Or he wouldn’t have a chance to turn into Gandalf the White. And looks like the men will need him anyway.
Okay, back to the Balrog. You’ll want to find the skinniest, ricketiest, oldest, least maintained bridge you can. Give yourself plenty of time to get across. Plant explosives at the weakest point, it’s probably in the middle where it’s the narrowest.
Okay now it’s time to find your weakest team member. They are going to be the bait. And I’m sorry it just can’t be the wizard. My pick is Boromir. Galadriel told you he’s going to try and take the ring. Wait that hasn’t happened yet, but come on everyone can sense it after that awkward moment in the snow when he was holding the chain. He’s already been corrupted. He’s a dick to Aragorn. Now a case could be made for Merry or Pippin, but come on they are hobbits and they’ll be needed to help treebeard destroy Saruman’s tower. Also it would be a dick move to kill off a hobbit, at least this early.
Okay everyone else get out of range of the fire whip. Place Boromir near the explosives. You should also use a dead-man’s trigger instead of a fuse just to make him feel more valuable and necessary.
I think having everyone just leaving the area as the Balrog approaches will make him more likely to try and rush across the bridge and not notice how fragile it is. Also having Boromir waving his sword about and yelling at the Balrog will help too. You don’t want that Balrog remembering it has wings and just flying across the gap.
I think to really cement the trap you’ll want Boromir to try and stab the Balrog, it certainly doesn’t have to be lethal, just get him in the foot enough to piss him off. Then have Boromir blow the bridge and he can ride that demon down to the pits of hell.
Boom everyone gets out.
That’s how you stop a Balrog.