Monstrosity!

She also got a rectangular-shaped artifact that looked like a booth. It was silver colored with a door. 

On entering inside and closing the door she could teleport to any location she pleased, the only problem was she had to have a visual representation of the location in her mind. She could have used this to teleport out of the sralaken beast but she had no visual representation of the venulus dimension since she didn't have the chance to even explore it before getting swallowed. This artifact couldn't travel out of the venulus dimension back to Beni city because the spatial power of the booth was not that powerful and even if it was Rin didn't want to leave the dimension. She would fail Alusec's test if she did. 

She stayed in that building picking a lot of treasures along the way. The next day she entered another building, this one was looked ancient. It had a greenish looking Statue of a cauldron.