If every one converts, then it will become a matter of which sect - Shia or Sunni - will come out on top.
The killing will continue until one or the other is supreme.
If the Sunni win, then they will kill each other until one or another cleric’s views are supreme and there is no dissent.
Should the Shia win, then it will be a matter of which sect inside the Shia sect wins by killing all the others.
If the 12ver Shia sect wins then they are obligated to bring what remains of the human race to paradise ... that done, the last two must kill each other ...
Does that answer your question?
In other words, the killing never stops.