Kanaya seemed to have lucked out in regards to the costumes -- that is, she didn't appear to be wearing one at all. She looked a bit of a mess, but it was a rare time when she didn't.

She didn't seem to recognize either boy as she passed by on the way out of the kitchen, oatmeal in one hand and chainsaw cradled in the opposite arm. (If there was one thing that Kanaya liked to be prepared for, it was Tower monsters.)

She actually could have pulled off a "chainsaw murderer" costume if someone didn't know what she looked like normally.