Okay, this has happened a few times and lately last night on the map "Free for All" an 8-player scenario where I play as Dungeon vs 7 enemies. Suddenly, completely out of the blue, an extremely powerful AI hero shows up on the Thieves' guild page; this time Isra with stats of 24/22/23/22... It's month 2, week 1 and extremely unlikely that anyone has gotten THAT powerful.

On random maps, occasionally an AI hero will get really strong but you can usually follow that process via the Thieves' guild. For example, in one scenario, Pyre started by finding some good artifacts so day 7 her stats maybe looked like 7/6/2/3. Then she leveled some and found some more artifacts, so, next week maybe she was 9/7/8/6. And eventually she took a Dragon Utopia and found something like the Helm of Heavenly Blessing so she's +6 all stats making her 17/13/16/12. And then some more artifacts, eventually she had stats of 20+ in everything.

But this happened overnight; Suddenly Isra is purple's most powerful hero (up until that point, it has been Tamika with 6/7/4/1) with stats of 20+! It makes no sense and it's extremely unlikely that purple suddenly found all the artifacts of the Agelic Alliance, assembled it, and then put it on a secondary hero...especially since the Lion's Shield of Courage is literally under my nose, I'm about to attack some ancient behemoths for it!

This has happened before, most notably on one of my own maps; I had just taken the 2nd city, it was end of week 1 and I notice in the Thieves' guild that my enemies have Josephine with stats of 7/7/5/5 which is not possible because there are barely any stat boosters on the map, and there are no artifacts that powerful only +2...I restarted that map and never had that problem again.

So what can I do? Can I hack the save somehow and fix this? I've invested a whole day IRL on this scenario, I don't want to lose due to a bug.

The "Best hero" is the one with the largest army. So occasionally, at the start of a new week, the "Best hero" will change to the one who's bringing out the army, but, most players (and the AI aswell) will want to transfer those troops to their most powerful hero ASAP. Which means the best hero usually stays the same over the course of them game.

I found the solution to my problem however; apparantly the Angelic Alliance spawned in Purple's starting area guarded by several Phoenixes... I had no idea combination artifacts could spawn fully assembled like this, but it did.

You managed to beat her?