User blog comment:Hitsuji Mamoru/Servant Creation Room 2 : Guess of the Who/@comment-4802891-20170404162419/@comment-4802891-20170412101437

Neither of the two, and you are both pretty far.

I will give you a few more information :

1/ This Servant is an abnormal Berserker and shouldn't be of this Class.

2/ Its existence is akin to a famous biblical demon, but this is just an effect of its abnormal summoning

3/ The body doesn't match the mind, so you can consider this character a genderbend