Ran'ji > WoD + Oracle of Light + Scorn!?

[Kallera]

^ Above mentality discredits the untold number of years/generations he fought against the Sin-Eaters, training those Minfilia's and seeing them cut down, time and time again. This wasn't some rando who saw Vauthry and immediately bent the knee - this is a chap who was likely Numero Uno in the Sin-Eater slaying department on the First who had nothing to show for almost a century of fighting but constant defeat (or as close to it as you can get without being wiped out). Then Emet comes along, instigates the birth of a human Sin Eater who can control those beasties. You'd be tired too after all that time and far more susceptible to the notion that maybe throwing your lot in with that obese scumbag would be preferable to fighting for the losing side which now also has people defecting/mind-controlled and bleeding out numbers without even fighting at all. If not for himself, then for the other Minfilia's.

Ran’jit did seem to be acting so that there won’t be any more minfillias fighting and dying to sin eater hands.

This is an old man who has bore the pain of seeing little girls he raised fight and die on the front lines, in a war that was well on its way to defeat. Its not like Thancred broke the cycle either, even with the sin eater threat gone, all. that depends on what happens if/when Ryne dies.