**SPOILER ALERT** First of all I think there were two killers not one...
One is with the gun. The second is with the knifes.
Look at where Agni is attacking:
http://www.mangago.me/read-manga/kuroshitsuji/an/kuroshitsuji/127/pg-5/
But then he is attacked from the side with a knife:
http://www.mangago.me/read-manga/kuroshitsuji/an/kuroshitsuji/127/pg-6/
And then the killer said that he'll take care of the rest.
http://www.mangago.me/read-manga/kuroshitsuji/an/kuroshitsuji/127/pg-8/
I think if the killer had both knifes and a gun then he would had killed Agni with a gun and finished him off much quicker...
Secondly... I think the one with the gun is "Ciel" aka our Ciel's twin brother...
Why?? Because it was obviously someone the prince knew.
http://www.mangago.me/read-manga/kuroshitsuji/an/manga/kuroshitsuji/v18/c126/pg-19/
And then the writing in Ciel's room...
http://www.mangago.me/read-manga/kuroshitsuji/an/kuroshitsuji/128/pg-13/
It is something really childish and somethings kids might use to play or something. Sebastian clearly has no idea what that means while Ciel seems traumatized. In other words, Ciel know of this statement since before he met Sebastian.
Later, Ciel is shocked to see his burned picture in Agni's hand but he doesn't seem to be upset that Agni saw the picture... He seems to have something else on his mind.
http://www.mangago.me/read-manga/kuroshitsuji/an/kuroshitsuji/128/pg-16/
Well, that's what I think anyway (〜￣△￣)〜
2017-05-31 17:09 marked
I'd probably only be main character in a spinoff of the actual story cause in reality I don't stand out either lol. I'd be that guy who found out that his friends are Gays, accidentally saw them doing stuff, questioning his sexuality, refused to believe what his life had become and met a guy whom later he loved dearly.
2016-12-16 14:17 marked
Okay this question maybe sound crazy but well i just curious~ So please answer it if you please and have any... *grin* Mine probably Ass fetishes... i don't know where this fetishes strike me but i found it very alluring to see a guy rub his p*nis between another guy ass- i realize this fetishes while i read S+Yumiya One Piece doujin titled Secret......
2016-07-03 15:29 marked
Just a theory...