Pihen, the Burning Balance

Vigilance, impunity (As long as this creature is untapped, spells your opponents cast that target it cost {1} more to cast.)
When Pihen, the Burning Balance enters the battlefield, if any player has at least ten more life than their starting life total, that player's life total becomes equal to their starting life total.
If a player would gain life, Pihen deals that much damage to that player instead.