Burn the tree, enslave the kitsune, no diplomacy, no negotiation, only debauched degeneracy!
The Champion and the companions are bad ass, but that idea just won't fly. Nakano with his detachment, Azami and her underlings, Takahiro, Miko and Mai, Komari and EVERY Kitsune that likes their home NOT be a pile of ashes would just swarm you. And even IF the Champion managed to do all that, Keros would probably turn the Champion into a frog or something and stick them in a pond in the Astral Plane.
That doesn't sounds like a bad idea.
How about a corrupt champion tryin to attack the kitsune, and gets bad ended by Keros.