I love that turn of event. I think Koichi will try to prevent Endy to attack or hurt Pop, so Endeavor will first see Koichi as a villain but Koichi will at the same time try to save people from pop or try to stop Pop so Endeavor will see that he is on the good side. Either that or Endeavor will fight 6 or explosive Nomus.
But I don't think Endy will go full serious because this means death for everyone.
And the final between Pop and Koichi has to happen so I think Endy will be busy by Nomus or else at one point.