Three years passed after the battle with The Master Ramme.
These three years were full of a hard work! First, Xue Ren got a lot of people by swallowing up all the territories of the fallen master... He didn't really kill many 'aides' and 'leaders', but in order to show off some of his power, Xue Ren got forced to kill.
It was all done silently, so that it looked like the one who done it was Guri!
Xue Ren wasn't really interested up in taking up a high role. Furthermore, he had scars from Milliane on his face, so it wasn't wise to appear in front of everyone just like that.
He continued to raise the strength of the siblings while letting them face a lot of challenges. For example - killing the direct lineage of Master Ramme.
It wouldn't be wise to keep them up alive as it was clear they would search for vengeance sooner or later. It was also a good challenge and test for the siblings, whether it's their own battle power or leadership.