2 questions, first can you increase illusion spell durations at all? Second, I have an overpowered ward that says it negates like 400,000 damage but is easily destroyed by a mage dual casting even after it is fully charged. It only seems to be negating the standard 80 damage.

I can answer the first question.

Yes you can increase illusion spell duration. For best results, use alchemy, enchanting and of course perks. Alchemy and enchanting work together well.

EDIT: You can increase any spell duration using enchantments, and I think you can do the same with alchemy.

But as far as I know, the alchemy effect increases the level that the spells work on and the enchantment takes the magicka cost down so which effect increases duration?

The duel casting perk in illusion will increase the duration.

isn't there an effect like an enchantment or something? even if you can only get it through console. also, what about the ward problem?

Thats weird about the ward. Do you use any mods or the restoration loop?

No mods, just the fortify restoration alchemy effect on a ring. Other restoration spells are op'ed fine.

I believe all defence caps are hard. If you have armor beyond the defence cap, it doesn't add anything either.