Whenever Nafs Asp deals damage to a player, that player loses 1 life at the beginning of their next draw step unless they paybefore that draw step.
10/4/2004 If its damage gets redirected to its controller, it will still trigger the ability.
10/4/2004 The player can pay the mana at any time after damage is done before the draw step of that player’s turn. People commonly pay during upkeep.
10/4/2004 If it damages a player twice, they get to pay or take damage twice during their next draw step.
10/4/2004 The ability does not cause itself to trigger again. It cause loss of life, and not damage.