Bonfire of the Damned > Street Spasm if you really wanna make this great.It looks like you're just trying to use all the spoiled Izzet cards though.If you're thinking of something to build for when RTR is released, you may want to go ahead and prepare for rotation too and remove the rotating cards from the list.Just some thoughts.

Gotta say, I love Izzet Charm and plan to utilize it in my own Izzet Delver deck after rotation.

Since it's in standard, Izzet cards and Scar block cards won't be in at the same time

Also Mana Leak and Ponder will be rotating out when Izzet Charm rotates in.

Even in a format where you could use all these cards together, I wouldn't use Goblin Electromancer . You only benefit from his ability when you play Mana Leak and Street Spasm , roughly a third of your instants and sorceries

Mana Leak with Izzet charm?

I want to see you trying that one.

You don't need Invisible Stalker , i'm currently running him in my deck, but i think he will be useless compared to Guttersnipe . Also, Oblivion Ring is good but its better sideboard, because it doesn't interact with Delver of Secrets  ^Flip , Snapcaster Mage , card:Runechanter's Pike, Guttersnipe (if you run it) ect. I would play with 4 Snapcaster Mage and i would run Cyclonic Rift , Mizzium Mortars , or Azorius Charm in place of O-ring

No Epic Experiment into Worldfire?

4x Hallowed Fountain , 4x Steam Vents , 4x Sulfur Falls , 4x Glacial Fortress , 1x Clifftop Retreat , 1x Plains , 1x Mountain , 1x Island , 2x Desolate Lighthouse .

That's a much better land-base for this deck.

I think you should cut down the shocklands by 1 of each because you dont want that much lands that can kill you rather add some more islands plains or mountains for the sulfur falls and the glacial fortress I have a deck almost exactly like it [uwr-usa-delver]

• UWR (USA) Delver

I think personally you could drop Counterspell for Remand and make it modern legal, where the deck could run better than if it was dropped into legacy.

I would also have to drop Ponder and Preordain though and I don't know what I would replace both of those with, as they are huge staples of the deck.

You can make it modern and run Serum Visions, also adding a few creatures wouldnt hurt Snapcaster Mage and Vendilion Clique are both great. I dont think you can run this in Legacy, everything just destroys you.

The deck seems good, but there are some cards that could be out of it. Think Twice is not a great card for you, since you want to run in legacy, you have some better options, like Brainstorm, or Gush, these work better in what you want.

Bonfire of the Damned it's a card that I'm not a big fan, so I would take it out, maybe in place of Wrath of God, if your objective is to destroy everything in the field, or Fireblast to deal with the final blow.

You should also run the playset of Young Pyromancer, he does wonders in these kind of decks and it will bring you a better pressure to the field.

These are only some suggestions and feel free to argue them.

No doubt a +1 well deserved

Note to all: This deck hasn't been updated in 10 months.

If this is Legacy, why aren't you running Tundra, Volcanic Island, Force of Will, Daze, Monastery Mentor, et al?