The series is supposed to have two 5-part sections. So while many predict Todium will end the book by escaping Roshar, there has to be some type of positive conclusion for the 5 books as a whole. So maybe the tie idea where neither can win or they are locked in eternal struggle, and the loophole then results in all-out war where the Fused are defeated, Roshar united, but Todium escapes (and maybe kills Cultivation) is my best guess.