You aren't a big fan of the guy, but since these are supposed to do something special together, you figure what the hell.
You easily deduce the code Jake was trying to remember. It's uROBuROS. Come on Jake, use your head. Haven't you ever heard of the mythical snake biting its own tail? You worry about that kid sometimes.
Anyway, obviously the code for his juju was going to be the same as Calliope's, but written in the reverse case to match his quirk. Once again your gumshoeing skills pay huge dividends.