Amethyst Archdaemon's Dragon will be the key to freeing Jack.
We still haven't seen what Amethyst Archdaemon's Dragon's special ability is. My theory is that we'll see it when Wiraqocha Rasca duels Yusei, he'll use it to nearly win, while Yusei is trying to free Jack. Eventually, he'll realize that in order to do so he has to free Jack's soul, Red Daemon's Dragon. He'll then grab Amethyst Archdaemon's Dragon off of Wiraqocha Rasca's field, echoing the way Jack acquired Wiraqocha Rasca in the first place, and use his signer powers to transform it back into Red Daemon's Dragon, which he will use to win the game and free Jack.
Carly will keep working with Aslla Piscu even after she is no longer a dark signer
I'm pretty sure Carly will be freed eventually, but she seems very loyal to Aslla Piscu, and Aslla Piscu in turn seems loyal to her. I think that once Jack is free, he'll convince Carly to stop trying to end the world as well. However, I think that Carly will be too loyal to Aslla Piscu to fight against him either. I think a combination of this, the fact that Aslla Piscu doesn't seem to have a motivation to end the world outside of it being what the earthbound immortals were made to do, and a grudging acknowledgement that if the human race has members like Carly then it must have some redeeming qualities will cause Aslla Piscu to turn against the King of the Underworld alongside Carly, turning from a being of negative darkness into a being of positive darkness.
