I have a related question.
I was really curious why Yorick's ghouls do not proc spell effects (rylais, liandrys, and Death Fire Touch)? I thought that DFT would be a great mastery for him similar to Illaoi but it does not proc on his ghouls like it does for every other minion created by a champion in the game as far as I know (zyra, heimer, malzahar, mordekaiser, elise, annie, Ivern all have pets that apply rylais and thus should also apply deathfire touch). This behavior is really odd and unique to his ghouls/maiden and makes understanding what champion created minions should and shouldn't apply harder to understand.