Heat oil in a skillet over medium heat. Cook and stir kielbasa and onion in the hot oil until the onion is tender, 5 to 7 minutes; set aside.
Stir chicken broth, turnip greens, great Northern beans, vegetable soup mix, hot pepper sauce, garlic powder, Creole seasoning, salt, and black pepper together in a large saucepan; bring to a boil. Stir kielbasa mixture into the boiling broth mixture, reduce heat to medium-low, and cook at a simmer for 2 hours.
