Seems like this would be the best moment to attack Avoros and his troops, seeing how Avoros is comromised, needing to sync with the core. I bet there are still a few people working in the demon lord palace but in reality serving Avaros. Eve has such a flimsy grasp on power anyway that even her closest people barely trust her with any important stuff. So, I bet those geezers in fact have a pretty good idea who might be more sympathetic to Avoros's cause and who might thus be able to lead them to Avaros's headquarters. But of course they will do no such thing because Eve is more or less a demon lord in name only.
I'm sure those old powerhouses like or even love Eve, but she's not a true demon lord in their eyes. Don't be fooled by that performance by Marione. He's like a grandpa pampering his beloved granddaughter, not like a general serving his monarch.