2016-11-08 : Charging Cinderhorn’s triggered ability doesn’t trigger at all if a creature attacked this turn. It won’t get a fury counter or deal damage.

2016-11-08 : Charging Cinderhorn’s triggered ability triggers at the beginning of each player’s end step if no creatures attacked, including yours, and even if it wasn’t on the battlefield during combat.

2016-11-08 : If Charging Cinderhorn leaves the battlefield in response to its triggered ability, it won’t get a new fury counter, but it will deal damage equal to the number of fury counters it had before leaving the battlefield.

2016-11-08 : If a player loses the game during that player’s own turn, the turn continues to completion. If no creatures attacked, Charging Cinderhorn will get a fury counter even though it won’t deal damage to any player.