Cast Beacon of Tomorrows either from your hand or from exile by paying ({6} magic symbol) ({U} magic symbol) ({U} magic symbol) , causing you to take an extra turn after this one and shuffle Beacon of Tomorrows into your library.
At the beginning of your end step, Conjurer's Closet triggers, blinking Hoarding Broodlord.
When Hoarding Broodlord enters the battlefield, it triggers, searching your library for Beacon of Tomorrows and exiling it.