User blog comment:Hitsuji Mamoru/Servant Creation Room 2 : Guess of the Who/@comment-30314236-20170329170644/@comment-30314236-20170330223206

His traits? Well... Humanoid, evil and male.

I know it's too little, so I'm telling this: he was given his name based on a disguise he used in actual history. The fiction tells a more... macabre version about why he was known by that name. Yes, it's not an actual name, but an identity given by people.