Greyjoy player navals in Qarl, and activates his "response." The lannister player proceeds to cancel with the Iron throne. The Greyjoy player stands qarl with "to be a kraken," the lannister player cancels with a paper shield.

My question is, after Qarl stood because of "to be" does the lannister's "Iron throne" kneel effect then activate?

It would seem to me that it would due to the way the timing works:

• Initiate Qarl's character ability
  • [save/Cancel window opens] Initiate Iron Throne's cancel of Qarl's ability
    • [save/Cancel window opens] Initiate To Be a Kraken to stand Qarl as a cost
      • [save/Cancel window opens] Play Paper Shield to cancel TbaK
        • [save/Cancel window opens] No cancel is played
      • Paper Shield cancel resolves
    • To Be a Kraken's cancel does not resolve
  • Iron Throne's cancel finally resolves successfully... the THEN effect now goes into affect and Qarl is, once again, knelt.
• Qarl's ability does not resolve

That's the way it seems to work in my head... but I'm still a Rules Acolyte.

So, Qarl triggers his ability which is cancelled by the Iron Throne (which should kneel him). GJ player uses TBaK to stand Qarl to cancel the Iron Throne - using a cancel to cancel the cancel... However, the dirty Lannister player foils this plan by cancelling the cancel of the cancel...

sorry, had to write that out to see how it interacts...

Given that Qarl is indeed standing when the cancel fest is over, meaning the Iron Throne did in fact cancel Qarls ability, it will (I believe) indeed kneel him.

Awesome, thanks for all of this!!

Your analysis is spot on, doulos2k.

Hmmm... It's interesting that the only time there is a stack is in cancel chains... LIFO to the rescue!