This is the load-bearing Igaram-true-identity reveal. The triple-disguise stack (Mr. 9 disguise-side Ch. 105 → Mr. 8 senior-officer-side Ch. 107 → Igarappoi mayor-front-side Ch. 106) collapses to the true-identity Igaram, Alabasta Royal Guard Commander in a single panel. The die-for-the-Princess loyalty doctrine is installed in the same chapter as the identity-reveal — meaning the reader meets the true Igaram for the first time already committed to dying for Vivi, not as an abstract loyalty-claim but as on-page combat-action (the booger-cannon body-block).
The escort-contract premise Igaram installs in Ch. 0110 page 19 (“Please escort my princess to Alabasta, a great kingdom in the far east!”) is the mechanism by which Vivi joins the Straw Hat Pirates as a temporary nakama. The recruitment-grammar that runs through the Alabasta saga is:
Igaram begs Sanji + Zoro to escort Vivi (Ch. 0110).
Sanji + Zoro relay the petition to Luffy (Ch. 0111+).
Luffy accepts Vivi as an honorary-nakama on the cause-adoption register.
The crew adopts Alabasta as their cause — fighting Crocodile becomes their fight, not Vivi’s alone.
This is the first instance of the Vivi-as-cause-the-crew-adopts recruitment grammar — distinct from the new-member-joins-by-shared-objective (Nami, Zoro, Sanji) and new-member-joins-by-rescue (Usopp, Chopper) precedents. Vivi joins by delegating-her-cause-to-the-crew-via-her-retainer. The pattern recurs (loosely) with Robin’s adoption at Skypiea, with Nami-Sky-Island temporary-nakama beats, etc.