Actually ended up killing this save- I quit and rebooted until the Gi missed the Chaos, but then a Fotia appeared, ignited the Chaos, and then with Chaos dying of Ignite damage before I got a turn, I couldn't use half-turn RNG resets to get out of the loop.
Also, to bring up that tenacious 'occasionally auto-exploring faster than your team bug,' let it be known that I once again started running ahead of my team with Swiftness in Anomaly during autoexplore. I don't know if it's confirmation bias or what, but it does seem like one of the obscure trigger conditions it has must be anomaly related...