this was so obviously gonna happen, like why the fuck does the alternate personality announce himself as a reincarnation everytime he appears. also put your helmet back on dude how fucking stupid are you
Rei would be like "I guess it's time for me to do seppuku."
Then, the reincarnator would be like negotiate to help him kill all other reincarnators.
Rei agrees, but feel hypocritical about it.
Then he does seppuku anyway. The End.
I def think the made is going to let the reincarnation in him slide, as he is basically the one who has been protecting Rei this entire time. He'll see the hypocrisy, but won't care because who wants his surrogate son to live a good life
I'm betting his master knew about it since way back when the saint was talking about making rai her personal purge knight and disclosed rai's alternate persona with him.