this is what truly happened at the reverie... i think it's 90% likely:
- cobra at the reverie asks other kingdoms what are the poneglyphs and questions the nature of the WG itself
- cp0 targets cobra and vivi --> cobra gets killed to save Vivi
- Sabo, who's there to save Kuma, saves Vivi and there is the famous fight with the two admirals
- Sabo is accused of both killing Cobra and taking Vivi