Caesars hallucinogenic gas
It's not Judge and Caesar, the mysterious person has been taking Cipher Pol agents hostages for two months.
I highly doubt Judge and Caesar were at Egghead during that time, also why the fuck would they keep the Cipher Pol agents as hostages.
Also Judge and Caesar can't order the Seraphims.
The Blackbeard Pirates like Devon and Laffitte are way more believable than fucking Judge and Caesar.
I don't know why you want it to be Judge and Caesar so badly, they already had their arcs.
The focus is now on Vegapunk.