Reloaded my saved games and this seems to only have been going on for about the last hundred turns, the rest of the history shows a more normal mana level.

Looks like this problem existed in the beta as well.

That's it for me then.  Have fun fighting a turbocharged Darken Rahl, 'cause I ain't doin it.

336 million mana, most of it having to have to have been generated in the last hundred turns  And yes, I jolly well did check to see if there were lots of mana buildings - it seems he doesn't even have Immortal Codex yet because there aren't any temples.  He probably has less mana-generating capacity than I do despite having twice as many cities!

No way that number is legit.

Maybe... but on one of my insane/epic games, magnar had six digit mana and not much gildar when karavox had six digit gildar and 3 digit mana (and later, magnar has 7 digit mana and six digit gildar).  Nine digit mana is still a few orders of magnitude beyond that.

That gives me an idea.... imagine if they introduced a new kind of difficulty level called 'incremental'.

Starts at easy and as the game progresses at various intervals the level goes up, eventually it will reach maximum difficulty!

Perhaps the AI is saving up for something big.  I think they added the Cataclysm spell.