To rise up, this master had to give his support to either monsters or masters, ending up with any of them to rise up in power, enough to break the shackles of this realm and go to the higher realm.
Once that happened, this master would leave the Spirit world for good, rise up from this low realm and go up to the higher one, claiming his past life.
That explained to William why spirits were this adamant at helping masters and monsters, and he also realised why such an issue was something very important to spirits.
As for why there was a conflict and difference in view between the spirits, it was explained in other series of scrolls. William learnt that not all spirits shared the same viewpoint about what happened to them. Many held grievances and bloody vengeance towards the higher power that punished them.
