What if I join the Jagni? What happens? - Biomutant Wiki
Joining the Jagni in Biomutant is a big decision. If you decide to Join the Jagni, your main quest becomes destroying all other tribes and helping the world eaters destroy the tree of life.
See also: Samurai, leader of the Jagni
Upon joining the Jagni you'll meet with their leader, Samurai, who explains his intention of destroying the world so it can start anew, or so he believes. Check out the Biomutant video above to see in detail how this all unfolds.