The Flame8
Prince
I'm on my fourth game now and I didn't see the AI summon the mercurians or infernals.
To be fair, one of these games was quite short as my capital was taken by orthus.
The other two were 500-700 turns in epic speed.
For the last game I'm at ~=350 turns in epic speed.
Interesting, anyone else? And try and normal speed, epic might take a while. That is one of my goals as I'd like the Mercurians and Infernals to enter the world more often.