Then why the real!Ciel killed Agni?

thats what i was thinking too :( Agni didnt have to die ;(

I think Undertaker has got to do with it because neither Prince Soma and Agni doesn't have enemies and our!Ciel warned them to never get involved with him because they'll get mixed up and I think Undertaker wants to take our!Ciel loved ones from him... I guess but we don't know what's his real goal is