Before his death, Asriel was known to be a docile, unadventurous, and loving child. After being brought to life again without a SOUL as Flowey, he became incapable of feeling joy, leaving him bored and resentful. After temporarily regaining his compassion, he apologizes for his actions to Frisk and realizes the gravity of his actions as a flower

Asriel has a soft, quiet voice, one of a timid child