Twenty.

"Sister Xue Ling, if a weapon's Will is clashing then do not force yourself in without an external help, please choose something else." Li Na tried to reason. 

However, Li Na's suggestion only fueled the reverse.

"Something's happening!" Li Na whispered, not sure of what to expect.

The hum turned into a resonant vibration, and the saber started to give off a faint glow. Ling Ling yelled out louder, as she poured her strength to pull out the saber from its rack. 

Then, with a sudden, sharp crack, the saber broke free from the rack, its weight causing Ling Ling to stagger slightly before she steadied herself.

For a moment, everything was still. Ling Ling stood there, breathing heavily, the dark saber trembling in her hands. She looked down at it, her expression a mix of triumph and awe.

"I told you," she said, her voice trembling but filled with pride. "This stupid junk is mine."