Bet it was some apology words or other words that would make Sam hug him immediately. (づ ̄ ³ ̄)づ Or it could be a 'Let's break up' message... #NOOOO Σ(  ̄□ ̄||)
The person that was greeted by Soma might be 'Ciel', since he talked to him in a friendly manner. The posture is of a child, too. But, the one attacking Agni has a taller figure, carrying knives, might be 'Sebastian'.
I'M FINE WITH NEW RIVAL OR STH BUT PLEASE DON'T LET ONE OF THEM DIE ┗( T﹏T )┛