Rayleigh is the main one, perhaps the only one, who received an actual upscale in these past two chapters. Everything else is reactionary fluff with no real bearing on the story. If Shakky were to be kidnapped, you can be sure he pulled something off at God Valley.
People forget it was Zoro, his parallel, who obtained the key during the Kaku fight that ultimately freed Robin from her cuffs. We have also seen Rayleigh destroy Camie's cuffs using Internal Destruction. So it's likely he freed Shakky himself and may have cut someone down to reach her. Assuming he didn't already have the epithet, this could be a cool origin for it as the dark horse who won God Valley's treasure.