Complex sentence: Gannicus again proves himself to be the champion of Capua and the god of the arena and by virtue of his win against Solonius' gladiators, becomes the champion of Capua and gains his freedom.
Split into simpler sentences: Gannicus again proves himself to be the champion of Capua and the god of the arena. By virtue of his win against Solonius' gladiators, becomes the champion of Capua and he gains his freedom.