Complex sentence: Baron Zemo leads the team in his revenge on Captain America and his Avengers, now joined by the Enchantress and the Executioner, Zemo found them in their exile to earth imposed on them by Odin.
Split into simpler sentences: Baron Zemo leads the team in his revenge on Captain America and his Avengers. The team had been joined by the Enchantress and the Executioner, who Zemo found in their exile to earth imposed on them by Odin.