Marchesa's Smuggler

Text:

Dethrone (Whenever this creature attacks the player with the most life or tied for most life, put a +1/+1 counter on it.)
: Target creature you control gains haste until end of turn and can't be blocked this turn.

Rulings:

• 5/29/2014 Dethrone doesn’t trigger if the creature attacks a planeswalker, even if its controller has the most life.
• 5/29/2014 Once dethrone triggers, it doesn’t matter what happens to the players’ life totals before the ability resolves. You’ll put a +1/+1 counter on the creature even if the defending player doesn’t have the most life as the ability resolves.
• 5/29/2014 The +1/+1 counter is put on the creature before blockers are declared.
• 5/29/2014 In a Two-Headed Giant game, dethrone will trigger if the creature attacks either player on the team with the most life or tied for the most life.