These are good questions. I think that looking at the reasoning behind the existence of the rules we’re discussing will help to understand this interaction.
The first two sentences of the third bullet point in the save entry provide much of this reasoning:
“If a constant ability or lasting effect imposes a condition upon a card that would continually drive it from play, any attempt to save that card must also remedy the ongoing condition. Otherwise, upon resolution of the save attempt, the card is immediately re-exposed to the ongoing condition, and removed from play.”
The above quote describes the situation which we would have with most save attempts against Dracarys: the save would resolve, and as soon as it resolves, the terminal condition kicks back in, and the card would be killed again.
Instead of allowing the potential for weird “phantom saves” in which players could establish ongoing terminal effects, and then firing off a series of saves (and in some way prospering off these saves with other card abilities), we established a general rule that you cannot save from terminal conditions unless the save effect also remedies the terminal condition.
In other words, it’s not that a save is somehow not able to resolve with regard to a terminal condition that establishes this rule, it’s that even if the save would resolve, the card would be immediately re-exposed to its terminal condition upon the resolution of the save, making the save ineffective. To prevent this situation, we created the rule that says such saves cannot be initiated unless the save effect also remedies the terminal condition.
So we get to the Dracarys (or any killed if STR is 0) interaction with Risen from the Sea.
A character is reduced to 0 STR, and is killed, and someone plays Risen.
The pre-then aspect of Risen saves the character. Upon resolution of the save, two things are imminent: the card is going to be re-exposed to the “-1 and killed if STR is 0” condition, and the post-then aspect of Risen is going to kick in.
These would occur simultaneously, so if the +1 STR from Risen is enough to remedy the card from the terminal condition, the play can be made.
Your other questions are a result of the way in which relevant RR entries are worded:
- First, since Risen's effect has two aspects, I am unclear how this section applies. Is the fact that Risen has a save aspect enough to make this text apply, even though it also has a +STR aspect?
The Save entry specifies “If the save effect does not also remedy the ongoing condition…”
The key here is that we are looking at the entire save effect, not merely the aspect of the effect that performs the save, to establish whether or not it can remedy the terminal condition and be used. In this light, Risen is seen as a single effect, with a pre-then aspect and a post then aspect. In evaluating the entire effect, Risen can save from a terminal 0 STR condition if it lifts the character above 0 STR.
- Second, I read the text here as not prohibiting the use of futile saves, but prohibiting the use of cards which have no potential to change the game state; why is it that playing Risen and forcing the Dracarys! math to update doesn't qualify? We know this could change the game state at least insofar as it would allow a second Risen to be played successfully?
I think that this is a case where an attempt to explain a situation in the RR is misleading. The sentence you are looking at has both a rule and the rule is then followed with an attempt to explain the situation, and I believe the additional explanation may be confusing the matter. The sentence in question is as follows:
"Therefore, if the save effect does not also remedy the ongoing condition, it cannot be initiated, as the effect has no potential to change the game state."
In the above sentence, the rule itself is very explicit:
"If the save effect does not also remedy the ongoing condition, it cannot be initiated.”
The “…as…” explanation following that rule not a conditional to the rule (in other words it does not say “…IF the effect has no potential…”) — the rule always applies, and the “as…” clause seeks to help people better grasp the basic case, but confuses the more complex case. Thanks for bringing it to my attention — I will seek to better clarify this interaction in the FAQ update.
In short, the answer to your second question is a strict application of the actual rule in this sentence: "If the save effect does not also remedy the ongoing condition, it cannot be initiated.” This is why a single Risen must be enough to remedy the ongoing condition, and if a single Risen will not suffice, you cannot stack them together.