Rishi's long-planned coup, in which his brothers depose Vinata's father, the royal children, and the House of Greens.
Asked how he can be authorized to make deals when the naga already have a king, Rishi answers that his brothers should have the current king — Princess Vinata's father — properly deposed by now, along with the remaining royal children, the prime minister, and the entirety of the House of Greens. He states plainly that the plot has been in planning for some time and that Carl's influence was meant to be part of it.
The uprising restores the long-defunct title of sultan, which Carl had thought was ancient naga history; Rishi signs his treaty as 'Sultan Rishi the Usurper, First of his Name of the Naga Uprising.' Carl dismisses the whole business as Game of Thrones bullshit and, learning that the contract would need re-signing by whatever leadership follows, marks Rishi for death anyway.
The coup that makes Rishi sultan and gives his contract its authority.