I think Saturn getting captured is the big event. A gorosei being captured will surely stun the world.
People overlook the fact that this Egghead arc can be a full scale war pretty soon. Just remember Sabaody when Luffy punched Charloss. They had to send Kizaru. Now, Kizaru alone won't suffice so if Luffy repeats the same feat of smashing Saturn after Vegapank tells him something that enrages him, the WG will send all its admirals to Egg head. Then we see RA making their move to capture Saturn via an intel also trying to save Vegapank can be a way.
RA and SHP with Grandfleet vs the Navy...