An admittedly unusual situation came up, and I'm interested to see if I interpreted it right.

Cthulhu vs Hastur, Cthulhu plays out Feathered Serpent and Yig.

Cthulhu commits the Feathered Serpent to a story.  Action window opens up, Cthulhu changes one of the [Terror] icons on the Feathered Serpent to a [Combat][Arcane], as per its ability.  Hastur responds with Socotophobia.

What icons does the Feathered Serpent have?

Here's how I read it.  Unfortunately, FAQ 1.11 doesn't work really well, as in this case, you can't just add up the icons, due to the "printed [Terror]" qualifier on Socotophobia.  So, first of all, one of [Terror] icons was already changed to [Combat][Arcane], so it keeps both of those.  Socotophobia removes all "printed" [Terror] icons - but that's only two icons left.  Yig adds one [Terror] icon, so that one remains.  Final icon count, [Terror][Combat][Arcane].

Alternately, you could read Socotophobia "printed [Terror]" as meaning "as many [Terror] icons as are printed on the card".  In that case, it's a simple matter of math:  Serpent has three (three printed, minus one transformed, plus one Yig), and then loses three due to Socotophobia, final total zero.  I don't favor that interpretation, however, as it's less intuitive.  The way Socotophobia is written, it sounds like you start with the character as printed, zero out all its printed Terror icons, then calculate what's left from there.

Which is correct?

 With your interpretation you have to tell weather Feather serpent changed on of the icons he from his printed icons or the bonus icon from Yig as it would change the result. I don't like that as you usually don't care and now it starts changing things, i'd prefer mathematical version of -3T, it requires getting used to but overall is simpler, but i don't know what version will Damon support.

actually, i dunno.

.Zephyr. said:

I'm not sure if there's any situation where it might be a bad idea for the Cthulhu player to not state that it's the temporary icon.

If there truly isn't, the problem goes away, since you can assume your opponent will always choose the temporary ones first.

jhaelen said:

I think the one situation where it would be a bad idea to use the temporary icon is in anticipation of Scotophobia. And if  Hastur player asked me which Icon I was electing to transform, I would start wondering why I was being asked and think through the possible outcomes - Scotophobia is one possible reason to be asked.  

Certainly it would either involve blanking Yig or doing something with "printed" icons.

 Always choose the printed icons. Th chances of your opponent destroying a supporting card granting an icon rather than the character receiving it is much lower than making the receiving character loose 1 or more icons.

The first result is  the correct one but for the process is slightly different. If the printed icon was selected to be changed, Scotophobia cannot in any way effect those gained from other sources. So the final count is Terror, Combat, Arcane. So technically both printed ones are considered blank/removed, but the game only considers that there is one until the effect wears off.