NEW LEAKED Modern Horizons 3 Eldrazi DRAGON Commander Deck Tech | Magic: The Gathering | EDH 

Thanks for the question!! In summary, you do not exile Worldgorger. When it enters, you exile Other creatures. Then if you use it as a sacrifice outlet for the emerge cost of another creature, it will get the leave the battlefield trigger which allows you to return all creatures you exiled back to your battlefield. You essentially blink all of your creatures whilst getting a reduced Emerge casting cost of the creature you are trying to summon. Make sense

Thanks for the question!! In summary, you do not exile Worldgorger. When it enters, you exile Other creatures. Then if you use it as a sacrifice outlet for the emerge cost of another creature, it will get the leave the battlefield trigger which allows you to return all creatures you exiled back to your battlefield. You essentially blink all of your creatures whilst getting a reduced Emerge casting cost of the creature you are trying to summon. One thing to note, as you need to exile all other permanents, you will have to tap the mana to have it floating for the emerge cost of the other creature you would like to bring in BEFORE you cast Worldgorger. The good thing is, they do not enter tapped!