Because she's a mouse. Quiet, timid, and all too eager to hide behind that hood of hers. Though I can't say I mind the last part.

[ She sighs. ]

... My last memories are of my death. I must have been unable to properly manifest as a Servant before coming here. [ Which does eat at her, a little, to know that she was unable to answer whoever called to her originally. Chances are they'd never have gotten along, but... still. ] ... But for some reason, I can exist in this place without a Master. Perhaps not at full strength, but I don't intend on forming a contract with just anyone.