I got it last night ( thanks to this place ) no quests other than u have to have the skyway unlocked ( by gaining senji's corner )
i found i could max its lv out at 28 but at the same time i find i run 3 minions while healing more so i prefer the vamp horrors for the bonus health while having to sac constantly (i like more mm assist then workin my butt of tryin to keep my own army )
its a great skill but sadly i am limited to 8 skills 0.o so i wont be using it as much