When Evan killed Carlos he didn't show any expression because he can feel the power inside his body was fading away.
He knew once the effect of shadow energy will end, he will once again feel pain just like last time.
And this time it will be even more terrible.
After two seconds the effect of shadow energy ended. This time the effect of shadow energy lasted for two seconds instead of one second like last time.
Valery was still looking at the headless body of Carlos with a shocked look on her face.
The mana inside her body was still trembling after Evan used shadow energy.
After she failed to stop Carlos even after using everything she got, she thought there is no chance for her and Evan to escape from Carlos.
After all, after transforming he was more powerful than a B rank hunter.