Xariah, the Errant

When Xariah, the Errant enters the battlefield,
you become the Monarch.
Whenever a player becomes the Monarch, they
gain control of Xariah, the Errant and all
permanents with any Enthralled counters.
{t}, Pay 4 life: Gain control of target creature
or planeswalker, it gains an Enthralled
counter, and becomes tapped.