Despite the many complaints by the weaker reincarnations, the original incarnation did not budge. He respected them and he knew that no matter what happened they would fight until their very souls became nothing, but he could not allow them to die before the true final battle.
"If we are to die wouldn't it be better to die in a real fight than to die against a projection of a memory?"
Even though the original incarnation said those words the other reincarnations did not want to acknowledge it, so he instead used force to convince them. As people who value their pride above all else upon being beaten by the original incarnation, the weaker reincarnations left. Now there were only about fifty of them left including Ren and the original incarnation.