Here I'll add a few things that came to mind while reading what others have been posting in here.
First, it would be interesting to reread the whole comic again under this knowledge, but that won't happen today
Still, I reread the parts where Jojo interacts with Parson and found a few interesting things.
Specially panel 9 in this update
about Parson being a Warlord or Caster and what type of Caster
Oh, he is a joker, he's a wild card. Better than an Ace, folks. He can beat everything! He can be anything!
and panel 8 in this update
about what the spell might really do
This is the trick. To make a wild card disappear
Also what Isaac says
about the spell in the last panel.
The spell might do what he claims. Or destroy you. Either way, our mutual enemy Charlie crafted it specifically to eliminate you
Also, two things about this update
Janis in panel 5 when meeting Parson
It's like... Looking at a little loose flame. When all the world is one great forest hex
And Marie in panel 9 about Jojo knowing Parson was coming
I only wondah how he knew you wah coming. That's hard Predictamancy...
We know/assume that Jojo knew about it through Charlie and Charlie knew about it through tapping into GK communications. Still it wouldn't surprise me if Charlie also had hired a good amount of predictamancy about this turn. It would be interesting to try to guess what might a tri-link between a predictamancer, the arkendish and Charlie as a carnymancer can do with predictions and Fate.
Now I'll put my tinfoil hat on.
I like the idea of starting a new side to get the portal to reopen.
First, since the city is now GK's, tell the dwagons to get out of the garrison by taking off.
Assuming Lex Doothis was not alone and had his stack of troops when travelling all through that great ocean and also assuming the SPW spell doesn't allow Parson to leave GK, he orders Antium to turn and start a new side to open the portal, get Sizemore and then turn back to GK. In the process he has to capture Parson to be able to start that new side and once the portal opens, asks Sizemore to get to Spacerock to stop the Inferno and also reclaim Parson back for GK.
Once the Inferno is under control and Parson is "decaptured" he goes to the portal room with Sizemore and sends him to get Wanda from the MK to decrypt everything in Spacerock. At that same time, Stanley orders all his Casters to get back to Gobwin Knob and since that's a direct order, they can't refuse. While Parson is at the portal room Antium turns back to GK thinking that's the right thing to do according to the plan Parson gave him (since it had been enough time for Sizemore to go get Wanda and come back) so the portal closes with Parson and Antium in Spacerock with a few red dwagons and all the rest of GK forces in GK.
So Parson dodged the bullet of the Inferno, pissing off Charlie and avoiding to use the spell, but is still in a complicated situation since he is in a poorly defended city far away from the rest of GK forces and will find himself against the wall again on Charlie's next turn where he will again be pushed to use the spell to get out of everything.