Then that's an interesting playthrough. You've gotten pretty close to the maximum boost to all fire spells. 2x30% Fire spells, +20% from the Prismatic helm - that's a pretty nice boost. The belt is also invaluable. The only thing coming to mind that you lack is the flame necklace (+15% Fire), but you do have better ones.
You also seem to have been taking mostly mana and int upgrades and few leadership upgrades. In any case, the game's been pretty kind to you - in 4-5 mage playthroughs from normal to impossible, I never had such strong item setup. I think it's very rare
