We were reading BNG FAQ, and noticed this line from it:

If you chose two targets and one is an illegal target when Sudden Storm resolves, that creature won't become tapped and it won't be stopped from untapping during its controller's next untap step. It won't be affected by Sudden Storm in any way.

However, according to recent discussion on Frost Breath and illegal target, the illegal target still doesn't untap due to 608.2b. This is also included in CI here: http://www.cranialinsertion.com/article/1030

So we'd love to double check if we had a misunderstanding on 608.2b, or there is a mistake on FAQ?

-Edwin Zhang

Sudden Storm
3U
Instant
Tap up to two target creatures. Those creatures don't untap during their controllers' next untap steps. Scry 1. (Look at the top card of your library. You may put that card on the bottom of your library.)

Frost Breath
2U
Instant
Tap up to two target creatures. Those creatures don't untap during their controller's next untap step.

Hi,

We're going to wait for the rules update for Born of the Gods to be released before we comment on this subject.

Thanks,
Nathan Long
Wizards.Com Boards NetRep

Edited Nathan Long (Jan. 22, 2014 11:40:36 PM)

Now that the Update Bulletin has been released, we have the answer. Here's a quote from the article:

608.2b
This rule talk about how a resolving spell or ability checks to see if its targets are still legal. If a spell or ability has multiple targets, it can still resolve as long as at least one of its targets is still legal. Here's where it gets fun. The rule specified that the spell or ability couldn't perform any actions on an illegal target, make that target perform any actions, or make another object perform any actions on the illegal target. This was a technical way of saying that illegal targets aren't affected by spells and abilities.

But there was a problem: spells and abilities could affect an illegal target without performing any actions. Consider Frost Breath. If one of its targets was illegal when it resolves, both creatures wouldn't untap during their controller's next untap step. This feels very wrong, so when Sudden Storm appeared in the Born of the Gods set, it seemed like a great time to address it. The change to this rule shuts down this hole. Illegal targets of Sudden Storm (and Frost Breath) won't be affected and will untap as normal.

So yes, this is a change - if one of the targets of Frost Breath becomes illegal, then the Breath wont' affect it at all - it will untap like normal during its controller's next untap step.

Thanks,
Nathan Long
Wizards. Com Boards NetRep