Complex sentence: Braxton initially attacks Chris, blaming him for their father's death, until Lamar shows himself to arrogantly chastise Chris, resulting in his death as Chris shoots him on the spot, to Braxton's astonishment.
Split into simpler sentences: Braxton initially attacks Chris, blaming him for their father's death. When Lamar appears and arrogantly chastises Chris, Chris shoots him on the spot, to Braxton's astonishment.