2016-07-13 : If you cast Nahiri’s Wrath without paying its mana cost, you’ll still choose a value for X and discard X cards.

2016-07-13 : If you copy Nahiri’s Wrath, it has the same number of targets and deals the same amount of damage as the original spell.

2016-07-13 : If you discard a card with {X} in its mana cost, X is considered to be 0.

2016-07-13 : Nahiri’s Wrath adds the converted mana costs of the discarded cards in whatever zone they were put into as a result of being discarded, even if they weren’t put into a graveyard (due to madness, for example) or are no longer in that zone.

2016-07-13 : The damage is not divided. Nahiri’s Wrath will deal that much damage to each target.

2016-07-13 : You can’t target the same creature or planeswalker multiple times to deal more damage to it.