Shiorii, Shade Touched

Shadow, Immortal (Spells and abilities cannot
reduce this creature's toughness less than 1)
Whenever Shiorii, Shade Touched deals combat
damage to a player you may pay {u/b}{u/b}{w/b}{w/b}. If you
do, each opponent's life total becomes equal to
the lowest amount.
Whenever a non legendary creature deals combat damage to you, exchange life total's with that
creature's controller.