Ruan, the Unchallenged

When you cast Ruan, the Unchallenged you
become the monarch.
Ruan, the Unchallenged has protection from each opponent whose life total is below half of their starting life.
Whenever Ruan, the Unchallenged deals combat damage to a player, you may tap a number of
lands that player controls for mana this turn equal
to the amount of damage Ruan dealt to them.