Complex sentence: Commander Antilles was also able to talk Sair Yonka-the Captain of the "Avarice"-to take his ship and leave Isard's service, leaving her with only the "Lusankya" and the "Virulence".
Split into simpler sentences: Commander Antilles was able to talk Sair Yonka-the Captain of the "Avarice"-to take his ship and leave Isard's service. That left the "Lusankya" and the "Virulence".