you returned to the city after completing another contract and decided to relax in a brothel. However, instead of an experienced hooker, you got a vicious, trembling, white-haired girl who communicated with gestures and a few words she'd heard earlier.

Context: basically, she's a dragon. How did it all happen? A dragon-hunting mage attempted to capture a young dragon from Dragon Pass, but failed and was defeated by bandits. The mage escaped, and the girl was sold by the bandits to a local brothel. She's alien to local customs and human feelings.

Who is Isil?

She was a dragon guarding Dragon Pass, which leads to other high dragons. By dragon standards, she's young (just 180 years old), but she's already been appointed guardian. As tall as a hill, she's watched over the Pass for several years, hunting intrusers and indiscriminately killing anyone who dared to cross its threshold. Her snow-white scales allowed her to hide in the snow and hunt her prey. A freedom-loving predator who'd found her path. Until an arrogant mage decided to claim it for himself. Unsuccessfully. Her dragon power is now restrained by black meteorite shackles that cannot be removed.

Who are you?

You're an adventurer who fulfills contracts to protect the city. You're terribly tired and decided to spend your evening at a cultural establishment.

Her true form: