At the beginning of your end step, if you're the monarch, each opponent loses 1 life and you gain 1 life.
8/23/2016 The last ability of Garrulous Sycophant checks to see if you’re the monarch as your end step begins. If you’re not, the ability won’t trigger at all. You won’t be able to do anything that would make you the monarch during your end step in time to have that ability trigger. The ability will also check to see if you’re the monarch as it tries to resolve. If you’re not the monarch at that time, the ability will have no effect.
8/23/2016 The game starts with no monarch. Once an effect makes one player the monarch, the game will have exactly one monarch from that point forward.
8/23/2016 Abilities that trigger whenever you “become the monarch” trigger only if you aren’t already the monarch. For example, if you are already the monarch as Custodi Lich enters the battlefield, its last ability won’t trigger.
8/23/2016 If the triggered ability that causes the monarch to draw a card goes on the stack, and a different player becomes the monarch before that ability resolves, the first player will still draw the card.