Ego.Parent() not setting parent
the wiki insists that you use Ego.SetParent(this.transform, child.transform) instead of the standard child.transform.SetParent(this.transform) but Ego.SetParent(this.transform, child.transform) doesn't actually set the parent child relationship Unity world/hierarchy wise so you have to use both, not sure if this is error on the wiki or a bug in the code
Following your previous issue, EgoCS is not supported to run in the editor. Therefore, trying to change the Hierarchy with EgoCS at editor-time is also not supported.
this time it was not during edit time, it was during play time in the editor (not sure if that makes a difference)