Complex sentence: When the Beet Warriors entered the city, they found him killing a Vandel Buster, and immediately engaged him in a fight, but were overwhelmed by Barasa's extreme speed.
Split into simpler sentences: When the Beet Warriors entered the city, they found him killing a Vandel Buster. The Beet Warriors immediately engaged Barasa in a fight, but were overwhelmed by Barasa's extreme speed.