Ways the arc can continue:
1. Lucci frees the Seraphim using the Bubblegun Stussy freed Kaku with. Seraphim can fly and easily catch up with the ship. Kizaru could, too, but, boy, have I given up on Kizaru doing anything here.
2. Blackbeard attacks Egghead. Knowing Teach he's monitoring the situation. Ace, a Fire Logia, was defeated by Blackbeard while trying to avenge his friend and protect his crew/captain, and old man. Kizaru, a Light Logia, just killed his friend. York would be SO valuable to Teach.
3. Sanji retreats to try to save Stussy
4. Labophase collapses, causing a Nuclear explosion when the Mother Flame breaks.
5. Imu sends Uranus to attack the Straw Hats (had plenty of time to do this if Uranus still has Mother Flame left after Lulusia).
6. Shiki or Enel attack Egghead (both connected to Ancient Technology).
Egghead began with the Seraphim attacking a pirate island they invaded, and Lulusia being destroyed by Uranus, with Sabo, Luffy's brother, another representation of the Sun, escaping.
Egghead will end with the Seraphim attacking the Straw Hats, fleeing a government island, and Uranus being revealed to attack the Straw Hats, I'd guess. But, S-Snake and S-Bear, because of Luffy and Bonney, will help defend the Straw Hats, and S-Bear will teleport everyone away. Ideally this teleport would be to Dragon on Kamabakka.