So back after a very long hiatus from dotp, I am back!
I've faired very well online with Izzet, so I'll go over my decklist.
The trick is you really need to be virtually uninteractable with your opponent. So creatures they can't kill, creatures that come back or creatures that gain you value, even if your opponent killed them. That is what this deck is all about.
Having said that, the decklist
3 x
Mana Leak 
3 x
Volcanic Geyser 
3 x
Arc Lightning 
3 x
Compulsive Research 
1 x
Cerebral Vortex 
2 x
Electrolyze 
2 x
Invoke the Firemind 
3 x
Petrahydrox 
3 x
Steamcore Wierd 
2 x
Wand of Elements 
3 x
Prophetic Bolt 
2 x
Time Warp 
1 x
Beacon of Destruction 
1 x
Tidings 
2 x
Izzet Chronarch 
1 x
Sphinx of Jwar Isle 
4 x
Terramorphic Expanse 
10 x
Island 
11 x
Mountain 
The whys:
Mana Leak : Only early disruption we have really, good for slowing down the aggro decks and vital to stop big bomby finishers.
Volcanic Geyser Tad bit expensive early but still fair support with your other removal spells, your opponent can't "kill" burn spells and the time you buy against many decks can make the scalability of this card become very relevant.
Arc Lightning Really poops all over aggro decks often 2-1ing them.
Compulsive Research Drawing is a vital part of beating control decks, as he who has the most ressources will win. This card is a very efficient draw spell.
Cerebral Vortex See Compulsive Research, the 2 damage is usually meaningless, but you can actually kill your opponent with this sometimes.
Electrolyze See Arc Lightning, this is slightly better, being at instant speed and drawing you a card, both are vital to surviving aggro.
Invoke the Firemind Not the most cost efficient thing in the world, but kills creatures vs aggro and draws you tons of cards vs control.
Petrahydrox Severly underrated, you
can't kill this guy, such an MVP vs control it isn't even funny, an okay blocker vs most aggro decks.
Steamcore Wierd Tramples on the aggro decks. Kill a guy and have an efficient blocker all in one? Yes please. Against control it'll do 2 damage no matter what, so you got value even if they kill it.
Wand of Elements I underestimated this card at first, but it's the real deal. My first iteration of the deck struggled against control, but no more. You draw so many card and have so much land that pitching away a few seems like such a small drawback. This card gives control nightmares, they can try and play all the spot/mass removal they want, but you will have a continuos stream of creatures, that they cannot stop.
Prophetic Bolt 4 damage kills alot of things, attach an instant speed
Impulse 
to the deal is great 2 for 1 value.
Tidings If we have gotten to 5 mana, then the only way we are going to lose is in the long game, this card ensures that we won't lose the long game as it is a very efficient draw spell.
Izzet Chronarch Whether it eats a removal spell or trades with a guy, it is a two for one. Choosing your most needed spell is very good. This goy will always give you value.
Time Warp My favorite combination of things is a late game Wand of Elements, followed by a Time warp, as it leads to so much unexpected damage, regardless at worst this card draws you card and give you another land to play, it usually does more than that and dosen't die to your opponents removal spells, which is why it got the slot over say
Dominus of Fealty 
.
Beacon of Destruction Pretty efficent removal/game ender, the fact that it shuffles back in is sort of relevent with all of our card draw.
Sphinx of Jwar Isle 5/5 flying finisher, that can't die easily, which fits pefectly with what the deck is trying to do.
Every other card dies to removal without giving you value or only does something like random damage to players, when we weren't putting pressure in the first place. (cards like
Act of treason 
and
Conquering Manticore 
)
Breaking Point 
is really bad, I even gave it a small sliver of doubt and tried it for a bit. It is really bad. Vs aggro? Okay I take 6 and now beat your face in with 8 damage of goblins/knights/red and white creatures or whatever. Vs control? Could be either or, whatever benefits the control player at the moment.
I'm pretty sure the decklist doesn't get any better than the above. Only other card i've thought about on occasion is
Reverberate 
.
What to do:
Vs. Aggro decks:
Mulligan aggressively for removal, particualrily
Arc Lightning ,
Electrolyze ,
Steamcore Weird 
and
Mana Leak most of all, don't keep hands full of 5 mana spells and you should be okay,
Wand of Elements is a little low priority here as well.
Volcanic Geyser is only okay, but you might want them against Goblins (because of Piledriver), that said against gobbos, you really want arc lightning. Sideboarding will include cutting some card draw for more creatures/removal, this includes
Razorfin Hunter 
,
Wee Dragonauts 
,
Gelectrode 
and probably some
Spellbound Dragons 
Vs. Control decks:
Keep any hands that have lots of land, you want to be able to keep up in land drops. You have alot of card draw to gain ressources later on. Wand of Elements is your savior here.
Petrahydrox and
Sphinx of Jwar Isle are fairly good as well. Not much when it comes to sideboarding, but I would cut a steamcore weird for a
Jester's Cap 
against alot of matches, such as lilianna's deck and Mana Maze.
Vs. Midrange-ish decks
More or less follow control game plan.
cost 
