Baa' Rhal, the Forgotten

You don't lose game for having zero or less life.
At the beginning of your turn, you lose 5 life. This loss of life cannot be prevented.
Whenever you cast a spell, if it's the second spell you cast this turn, you get a poison counter.
Whenever an opponent casts a spell, if it's the second spell they cast this turn, switch life totals with that opponent.