zipec

Hmm, you should probably run more creatures.

Well it sounds good at first, but then you realize that to fling Ball Lightning, you have to have 5 open mana. With Kiln Fiend its also very risky, you also must have open mana for fling + burn and he has to survive his swing.

Finally a deck where Guttersnipe fits (he is card more for a control). Your choice of spells is very solid and the deck is also not expensive.
If I may suggest a minor changes:
1) drop some (3-5) unsummon effects (4 Cyclonic Rift + 3 Unsummon + 2 Aetherize seems a little too much) for counterspells (Dissipate, Izzet Charm, Counterflux, or even Negate)
2) This is not exatly mill deck, so the other Jace (Architect of Thoughts) could be better.
If you want, look at my Izzet decks:
Standard version: http://www.mtgvault.com/zipec/decks/ru-izzet-pike/
Modern version: http://www.mtgvault.com/zipec/decks/ru-izzet-pike-modern/

Mizzium Mortars should definitelly be mainboard. Also consider Cyclonic Rift.

It will give them Undying. The problem is undying is quite weak in this deck, because Cackler and Stromkirk noble already got a +1/+1 counter if they do their job right.

I dont think your creatures are fast enough. In fact, they are suboptimal for modern burn deck. Guttersnipe is 3-mana, just worth running in standard decks, in modern too slow. Fire Servant is fine in multiplayer or EDH, but 5-mana support for burn doesnt work. Goblin Arsonist is only good to sacing into Goblin Grenade, but even then its 2 cards and RR for 6 damage - thats the same power as 2 Lightning Bolts, but the Bolts are more reliable. Bloodcrazed Goblin is quite restrictive, you can't hold your instants to opponents turn (bad especially with skullcrack against lifegain decks). Goblin Guide is just better.
Ball Lightnings, Spark Elementals, Hellspark Elementals would do the job better. Or you can have approach similar to me: http://www.mtgvault.com/zipec/decks/br-burn-modern/

With a lot of mana elves and primal surge goes well craterhoof behemoth.
On the contrary, X-Hydras dont like primal surge. :-)

Why Crypt Ghast? You scale with number of swamps, not with the number of {B} they produce.
Also Geths Verdict instead of Cruel Edict sounds good.

Consider Ajani's Pridemate.

Black Sun's Zenith clears your own board big time. I would not run it.
Your creatures has low power, Fireshrieker might not be the best equipment. I like Grafted Wargear. Its universal and powerfull equipment, auto-add in any equipment deck I considered. Could be good here.
Your creatures are low casting cost. Disentomb instead of Zombify can usually save you some mana. Also it gets around Grafdigger's Cage.

Hmm,
3 Fireblasts is too much (1 is just fine, you dont want 2 on hand)
add some more duals
I know the Undying Evil is in the name of the deck, but it really does not work with anything here, Vexing Devil + Undying Evil is not a Legacy-powerfull combo as explained elsewhere. http://www.mtgvault.com/noviax/decks/undying-devil/
I dont see use for Street Wraith.
I dont see use for Manamorphose
For some effective burn creatures: Goblin Guide
As your creatures are the best turn 1or turn 2, I dont think Disentomb is such a good idea.
You have very few creatures to run Madcap Skills

Surely you mean Archaeomancer. Well, he is an option, but he is 4-mana. I would like Snapcaster more, but he is way off budget on this one. :-)

Looks fine. Only cancel seems unnecessary. I would play 2 more Steelform Slivers instead of it.
Supreme Verdict is uncounterable anyway. Sideboard Rootborn Defenses against it. :-)

This exactly. The idea was thorously discussed here: http://www.mtgvault.com/noviax/decks/undying-devil/
But seeing how hard you depend on combo you got wrong, I worry this deck will not work as is.

Thank you, I love it when my decks inspire others. (That is one reason I started posting on mtgvault.)
The black is here actually for three reasons: Sorin, Lingering Souls, Vault of the Archangel.
White has nice supply of creatures with sweet effects attached to them so I tried to make every spell into immediate board presence preferably with utility effect. Sideboard focuses on utility creatures even more. Thalia against control. Banisher Priest and Frontline Medic against creature-heavy decks. War Priest of Thune and Leonin Relic Warden against aura decks and artifact decks and others.
In fact I considered Accorder Paladin. I can explain my thought behind Signal Pest: Accorder Paladin is strong, but too fragile. He baits trade with anything, basically, he never survives his first attack if an opponent has blocker. Signal Pest has evasion and is more subtle threat, so he tends to stay on battlefield and do his job longer. Sometimes, he even deals damage, with another battlecryer or with Sorins emblem. Also, he fits better on the mana curve :-) (him and doomed traveler makes for optimal 8 one-drops)

I would not change a thing, I like it how it is. Sure there are other ways to build Odric decks (I personally tried few different Odric decks), but this one is just fine. Good job, sir. :-)
If I had to make a change, I would remove Ajani, he is more into decks with fewer stroger creatures (although he is good with Mikaeus), Elspeth is the token lady, but she is not in standard now. You can wait for her return (or remake) in Theros.
And if you want to look at one of my Odrick decks, this modern one with battlecry theme I especially like: http://www.mtgvault.com/zipec/decks/wb-battlecry-mastery-modern/

A lot of strong creatures indeed. Nothing less, nothing more.
The problem is, its way of budget for common player. :-)
Imho it needs more ramp (Farseek or Elvish Mystic)

About the Kjeldoran Dead: you can't regenerate sacrificed creature, so it really works well only with Reassembling Skeleton.
Also the equipment and Brass Sqire seems out of place here.

I already like it more. You made good changes.
Slitherheads are fine, awesome with Lolteth Troll, solid with Varolz. If you want to push this more into aggro, Slitherheads and Rakdos Cackler are good choices. If you want to push it more into midrange(which suits golgari better) try Deadbridge Goliath and maybe more Elvish Mystics, also Slitherheads are better for midrange decks than Dryad Militants, because you can scavange on your bombs later.
Elixir is nice sideboard against mill but I would not mainboard it unless at least 1/3 of my opponents play mill.

Really solid. I see reason behind every card. Doesnt happen often but I actually wouldnt change anything major (maybe numbers of onedrops, more Experiment Ones or maybe 2 more lands instead of Syncopate)
Its not one of those "put every evolver in" decks. Also big plus it is budget.
I like it, +1.