Marineford Part 1
1. Play as Ivankov and defeat Kuma. Don't capture Smoker's territory beforehand or he'll end up retreating.
2. Play as Luffy and get Hancock to butt into your fight with Smoker. Do not approach Hancock first or she'll retreat and don't defeat Smoker right off. Instead, engage Smoker then attempt to engage Hancock. She will retreat and when you fight Smoker again, you will get the scene.
3. Play as Buggy and encounter Mihawk
4. Play as Jimbei and defeat Moria