The beginning of the end (including a little "gift from heaven" - not exactly fire based, but even Arch Devils and Heliophagii need a little variety now and again):
Note the paralyzed Tartarian Monstrum in the lower center - he eventually sees the light (with a little help from the Tartarian Chains), and joins up with our side.
Here is a screen grab of what was going on in the Abysian rear for most of the battle (at least once the devils left to attack the Ermorian rear). Osirus (our Son of the Sun Pretender) and Pedoseion (Father Illearth) were primarily working over the Doom Horror, though another Tartarian Monstrum weighed in for Ermor, along with a bit of chaff. Eventually, Osirus gets the Doom Horror to see reason (again, with a bit of help with the Tartarian Chains), and the Doom Horror joins up with the Abysians. Here's the shot of the rear area:
