I said it. I don't know if this is just my problem. But I can't seem to find an answer on what spells to use other than what I am already using. I have a level 184 Nord on my PS3. I think the spells rock on the lower difficulty levels like Novice, Apprentice and Adept....starts going down hill at Expert. But when I play on Masters and legendary. Most of the destruction spells just aren't effective against enemies. They do almost no damage on dragons or enemies. I can't use my conjuration because of some glitch with Alteration and the Atronach perk on console.

The magic school I have found useful has been Enchanting, some destruction spells...fire cloak, Illusion spells such as muffle and Invisible, perks from Alteration and most useful has been restoration.

Yes. Most destruction spells have no effect in these difficulties. If you're on pc. Sure...there might be a mod or some fix to this. But on Console. I'm stuck.

Enchanting allows me to fortify my one handed and archery skills to doing over 300 in damage plus the elemental enchantments on the weapons such as fire, ice, or electricity. Also enchantments to increase smithing do wonders to increase heavy armor ratings if your character has a maxed heavy armor skill like mine. Daedric artifacts such as the Ebony mail combined with fire, storm, or ice cloaks pile on more damage. But as far as a majority of the spells in destruction. No. I've had [censored] to no luck. So, all I've managed to do is combine melee with enchanting and using restoration and some alteration spells to polish off damage.

Does anyone have the same problem on console or what ever?

Illusion and conjuration spells are unaffected by the difficulty slider. So there is that. The issue with destruction is that the damage does not scale and there are few ways to increase damage. You can increase it 50% by perks, but legendary difficulty erases that completely, and then cuts damage in half again (since the PC only does 25% damage in Legendary).

If you invest in alchemy, you can create some powerful fortify destruction damage potions and powerful weakness to elemental damage poisons. Combining those, you will be able to do good damage with destruction even on legendary, but you will have to carry around a ton of potions and poisons, and may need to boost your potion making with enchant (though you can buy good fortify alchemy enchantments, so you don't actually need to perk the enchant skill). Unfortunately, alchemy and one or two unique enchanted items available in the DLC are the only ways to increase destruction damage other than those pathetically weak perks.

I've always wondered, if you're playing a mage that only uses magic with no weapons, how would you apply a weakness potion?

Give 'em a coupon for a free massage... (or get the poisoner perk in the pickpocket tree, and puts it in their pocketses...)

...and as to the OP, I use Illusion a lot. Frenzy on groups, cast fear on the last enemy standing, and sick a conjured whatever on 'em and watch them get chased all over. I love watching the argonian assassin being chased by a spectral skeever...

When I did it my mage carried an unsmithed long bow and iron arrows, but yeah, you have to use a weapon to apply the poison, so there is that.

I don't believe the atonach glitch affects bound bow and you can apply poisons to the bound bow if one wants to stay as magical oriented as possible.

Carry Atronach Stone as the 2nd Stone on the Aetherium Crown and it becomes much easier to use conjured creatures by removing the crown when you use summons.It's what I do on console.

Yeah, you could use bound bow, although that is a magicka intensive spell which could be problematic for a destruction build, depending on how much cost reduction you are using. But you are correct that bound bow is not affected by the atronach summoning bug.