Con-fed-up

Needs Khans of the Steppe. Confederations form between tribal or nomadic rulers of the same culture, so the wiki build is a custom tribal/nomad duke with the Diplomat trait whose culture matches a neighbour's. Butter up that neighbour (high relations are the acceptance driver), take the Call for Confederation decision, and have them say yes. About an hour's work, and it slots into the same steppe trip as Blood of my Blood and Settling In.