I had two ideas for this prompt and I liked them both equally, so I did both. Here is the first one, I played with the idea a little, I hope you don't mind. Also, Molly is here because wishful thinking.
The arcane field that separated her and Nott from their friends glowed a deceptively disarming light blue. Nott was shaking down by her feet. “I-I’m sorry!” she said, her voice shaking. “I’m so sorry, I thought I got everything, I didn’t see-”
“Nott,” Beau interrupted, because if she didn’t the small goblin would go forever. “It’s fine, this isn’t your fault. The trigger was arcane, so this is Caleb’s fault.”
Caleb frowned at her from the other side of the wall. “Well, that is rude. Perhaps I will not dispel it and free you now.”
“What!?” Nott exclaimed and Caleb’s face instantly softened.
“I am sorry, it was a poor joke. I will begin the dispelling now.” He sat down and started flipping through his book.
“Don’t you worry guys,” Jester said, grinning. “We’ll get you out lickity split!”
There was a noise from behind them, farther into the darkened room and, when they both turned to look the room was suddenly awash with light. Beau winced but didn’t close her eyes to let them adjust, and when she could finally see she couldn’t believe her eyes.
“What… the… fuck…” she mumbled, in shock.
The entire room was made out of white marble, so the light was harder on her eyes than it would have been otherwise. There was a large, glowing ball of light hanging from the ceiling with no discernable power source or anchor holding it up. There was a pedestal in the center with a single short sword sitting on top. The hilt was inlaid with several glittering stones and the blade itself was silver in color and glowed with a faint bit of magic. Across the room was a hulking, nearly transparent spirit in translucent armor, it’s eyes glowing red. She recognized the sigil on the front of his armor from the book she’d read before they ventured in here. This was the protector of the queen they’d come to grave rob. Shit.
“Fight me,” it said in a voice that shook that the walls. “If you wish to continue, you must prove yourself the superior sword fighter.”
“Holy shit,” Molly mumbled, he was leaning against the barrier now. “Hurry up, Caleb, I need to get in there.”
Caleb frowned at him. “It is not something I can hurry, it is a ten minute spell, it will take ten minutes no matter how urgent the situation.”
“Fuck,” he tiefling cursed again and he and Fjord shared a worried glance. “Is this the sword fighter we were told about, I guess? The one buried here to protect the queen?”
“I hope not,” Jester mumbled, twiddling her fingers nervously. “He was, like, the best fencer ever right? Beau can’t fight him, she doesn’t use swords.”
“Beau,” Fjord called, banging on the wall. “Just dodge and weave, do what you can to avoid him for as long as possible until Molly or I can get in there. We’re the best sword fighters here, we’ll run in when we can, just hold on.”
“The fight will start when my opponent picks up the sword provided,” the voice said again.
Molly sighed in relief. “Alright, it looks like we’ve got some time. Just hold on, you two.”
Beau huffed and started walking towards the pedestal. She picked up the sword and spun in around in her fingers. “You guys, I got this,” she said, sneering at them when they cried out for her to wait. The pedestal made a groaning noise and began to sink into the ground. “What the fuck do you think the monks taught me at that damn library? But, you know, I don’t like to show off.” With a flourish, she tossed the sword into the air and then caught it deftly, continuing to spin it and toss it from hand to hand with a practiced and surprising grace. When she was finally done proving her point, she turned to face the spirit once more.
“Don’t do anything stupid, Beau,” Molly called.
“Too late,” she called back, flipping him off without looking back at him.
“Fuck you!” he called. “Don’t die!”
Nott was holding Beau’s pants tightly in her fingers but let go when Beau gestured for her to go stand by the wall. “Don’t worry, I’ll keep him away from you. Just go stand still and don’t do anything.”
“Prepare yourself, intruder!” The words were so loud and seemed to be coming from everywhere, it briefly made her vision swim.
When the pedestal sunk completely into the ground the spirit began to change, becoming more corporeal and solid. He pulled a sword from the sheathe on his belt and started running towards her. Each step he made caused the ground vibrate under her bare feet. She held up the sword in front of her and stepped back into a defensive stance. Nott squeaked in fear and ran off to the far wall, pressing herself against the stone.
Beau smirked and flipped the sword around in her grip until the blade pointed down. She balled up her other fist and bounced lightly on her feet. “Come and get me then.”