Forum:Zombie master rulings and priorities

ok I have a question I have a zombie deck and my friend has a macro cosmos deck. Every time I summon Zombie master and I use his effect, he chains macro cosmos to the trigger effect of zombie master. Can zombie master still speacial summon a level 4 or lower zombie type monster. And if it still does its effect the monster that was discarted does it go to the graveyard or is it removed from play. Anyway this topic should be in the rulings so please make it possible to put in the zombie master's rulings. Thanks guys